Author Archives: Android Developers

3 Exercises To Get Your Fitness App In Shape

By: Mary Liz McCurdy, Health & Fitness Lead, Google Play

(Originally published on Android Central)

It's an exciting time to be a health & fitness app developer. With people shelling out on fitness more than ever before, we're seeing record high levels of gym memberships and attendance, the rise of boutique fitness, and an emphasis on connected devices.

Paramount to this growth is the integration of smart technology. Whether it be through streaming video, wearables, or mobile apps, technology empowers us with instant access to high quality workouts, sensor biofeedback, and endless on-demand inspiration. At Google Play, we've seen this growth reflected by the incredible popularity of health & fitness apps. In fact, this is one of Google Play's fastest growing app categories, boasting the most engaged 30d active users.

As the resident health & fitness expert on Google Play, I had the opportunity to speak about what's driving the category's growth at the recent Wearables Technology Show. Here are the top three recommendations I shared with the audience to help coach developers towards building more valuable app experiences:

Lose it!

#1: Be invisible

We all know how painful manually logging activity and biometrics is- be it calorie tracking, workouts, moods, or hormone cycles. Manual logging is actually the number one reason users drop off.

What you should do: Minimize distraction with automation wherever possible while maximizing value at the appropriate moments. Remember that you are in all likelihood a companion experience to the main event.

Lose It! makes food tracking easier by using your phone's camera and image recognition technology to identify foods and their nutritional information. Goodbye manual calorie counting!

Strava uses auto pause detection, recognizing when you are resting during exercise so you don't need to fiddle with your device and can stay safe and in the zone.

Freeletics

#2: Be personal

Investing in robust personalization has been the driving factor in improving app engagement and buyer conversion among many of our top developers.

What you should do: Personalize the experience for each user or distinct user cohorts by leveraging technology like the Awareness API, Fit API, Google Sign In, and Facebook Login to intelligently pull in relevant user data. Think about your first-time users, power users, high value users, etc. and treat them uniquely.

Freeletics personalizes onboarding and the overall app experience based on gender and fitness level leading to a 58% increase in weekly active sessions.

Workout Trainer by Skimble increased user engagement by 30% through personalizing training programs based on user fitness assessments, goals, and workout patterns.

Glow

#3: Be assistive

The rise of smartphones, wearables and IoT have left us swimming in data and dashboards and left many consumers wondering, so what?

What you should do: Offer insights and suggestions, not just raw data. Users are not engineers and generally do not want to process complex data or dashboards. In most cases, they want you to tell them what to do in the moment or provide digestible summaries after the fact. Keep it simple.

Glow provides personalized insights that leverage user-inputted data and third party data from Google Fit to help couples achieve their fertility goals.

Beddit gives personalized daily tips to improve your sleep and wellness by analyzing sleep cycles, resting heart rate, respiration, room temperature, and more.

At the end of the day, changing health and fitness habits is hard. Make it easier for your users by seamlessly guiding them on what they personally need to do to achieve their goal. It's that simple ;) We encourage you to experiment with these exercises to get your app fit for the millions of Android users looking to live a healthier, happier life.

Now available: Android 7.1 Developer Preview

Posted by Dave Burke, VP of Engineering

A couple of weeks ago we announced that a developer preview of Android 7.1 Nougat was on the way. You can get started with this new release today by downloading the SDK and tools. To get the 7.1 release on your eligible device, enroll your device in the Android Beta program. If your device is already enrolled, you'll receive the update automatically.

What’s in the Developer Preview?

The Android 7.1 Developer Preview gives you everything you need to test your app on the new platform or extend it with new features like app shortcuts and image keyboard support. It includes an updated SDK and tools, documentation and samples, as well as emulators and device system images for running your apps on supported devices.

We’re continuing the model we used in N and earlier releases, and with Android 7.1 being an incremental release there are a few differences to highlight:

  • Since 7.1 has already launched on Pixel, we’re delivering the initial Developer Preview at beta quality for the Nexus lineup of devices. The goal is to tease out any device-specific issues.
  • We’ve finalized the new APIs as API Level 25
  • We’ve opened up publishing on Google Play for apps targeting the new API level, so you can update your apps soon as you are ready.

After the initial preview release, we plan to deliver an update in November followed by the final public release to the Android Open Source Project (AOSP) in December. Initially available on Nexus 5X, Nexus 6P, and Pixel C devices, we’ll extend the Developer Preview to other devices in November.

Get your apps ready for Android 7.1

To get started, update to Android Studio 2.2.2 and download API Level 25 platform, emulator system images and tools. The final API Level 25 SDK is available for download through the SDK Manager in Android Studio.

Once you’ve installed the API Level 25 SDK, you can update your project’s compileSdkVersion to 25 to build and test against the new APIs. If you’re doing compatibility testing, we recommend updating your app’s targetSdkVersion to 25 to test your app with compatibility behaviors disabled. For details on how to set up your app with the API Level 25 SDK, see Set up the Preview.

If you’re adding app shortcuts or circular launcher icons to your app, you can use Android Studio’s built-in Image Asset Studio to quickly help you create icons of different sizes that meet the material design guidelines.

The Google APIs Emulator System images shipped with the Android API Level 25 SDK include support for round icons and the new Google Pixel Launcher. The Google API system image allows you to test how your app’s circular app icons look in devices that support circular icons. Also, if you are developing live wallpapers, you can also use the the new system images with the Android Emulator to test the enhanced preview metadata in Android 7.1.

To help you add image keyboard support, you can use the Messenger and Google Keyboard apps included in the preview system images for testing as they include support for this new API.

Along with the API Level 25 SDK, we have also updated the Android Support Library to 25.0.0. The new version lets you add image keyboard support with compatibility back to API level 13. It also introduces BottomNavigationView widget, which implements the bottom navigation pattern from the material design guidelines.

For details on API Level 25 check out the API diffs and the updated API reference on the developer preview site.

Image keyboard support on Nexus 6P

You can use the Android Emulator in Android Studio to test your circular app icons & shortcuts in a launcher

App shortcuts on Nexus 6P

You can use the Image Asset tool to quickly create circular icon assets.

Publish your apps to alpha, beta or production channels in Google Play

Since the Android 7.1 APIs are final, you can publish updates compiling with, and optionally targeting, API 25 to Google Play. You can now publish app updates that use API 25 to your alpha, beta, or even production channels in the Google Play Developer Console. In this way, push your app updates to users whose devices are running Android 7.1, such as Pixel and Android Beta devices.

How to Get Android 7.1 Developer Preview on Your Eligible Device

If you are already enrolled in the Android Beta program, then your eligible enrolled devices will get the Android 7.1 Developer Preview update right away, no action is needed on your part. If you aren’t yet enrolled in Android Beta, the easiest way to get started is to visit android.com/beta and opt-in your eligible Android phone or tablet -- you’ll soon receive this (and later) preview updates over-the-air. If you have an enrolled device and do not want to receive the update, just visit Android Beta and unenroll the device. You can also download and flash this update manually.

We welcome your feedback in the Developer Preview issue tracker, N Preview Developer community, or Android Beta community as we work towards the consumer release in December!

Coming soon: Android 7.1 Developer Preview

Posted by Dave Burke, VP of Engineering

Today, we’re taking the wraps off of Android 7.1 Nougat, the latest version of the platform. You probably saw a sneak peek of it at last week’s event. It’s an incremental update based on Android 7.0 but includes new features for consumers and developers — from platform Daydream VR support and A/B system updates to app shortcuts and image keyboard support.

We’ve already been working closely with device makers to get them ready for Android 7.1, and next we’ll give you access to this update so you can start getting your apps ready.

Later this month we’ll be bringing you the Android 7.1 platform as an open Developer Preview, similar to what we did for Android 7.0. You’ll be able to test and build on the new platform and try the latest features.

As always, we’ll deliver the Developer Preview through the Android Beta program, which makes it incredibly easy to participate.

What’s in Android 7.1?

Android 7.1 delivers the productivity, security, and performance of Android 7.0, along with a variety of optimizations and bug fixes, features, and new APIs (API level 25).

For developers, Android 7.1 adds new capabilities to help you drive engagement in your app and deliver an improved user experience, such as:

  • App shortcuts API — lets you surface key actions directly in the launcher and take your users deep into your app instantly. You can create up to 5 shortcuts, either statically or dynamically.
  • Circular app icons support — lets you provide great-looking rounded icon resources that match the look of Pixel and other launchers.
  • Enhanced live wallpaper metadata — lets you provide metadata about your live wallpapers to any picker displaying the wallpapers as a preview. You can show existing metadata such as label, description, and author, as well as a new context URL and title to link to more information.

Android 7.1 also adds these much-requested developer features to the platform:

  • Image keyboard support — expands the types of content that users can enter from their keyboards, letting them express themselves through custom stickers, animated gifs, and more. Apps can tell the keyboard what types of content they accept, and keyboards can deliver all of the images and other content that they offer to the user. For broad compatibility, this API will also be available in the support library.
  • Storage manager Intent — lets an app take the user directly to a new Settings screen to clear unused files and free up storage space on the device.

For carriers and calling apps, the platform includes new APIs to support multi-endpoint calling and new telephony configuration options.

Image keyboard support on Nexus 6P

Image keyboard support: Let users input images and other content directly from a keyboard.

App shortcuts on Nexus 6P

App shortcuts: Use app shortcuts to surface key actions and take users deep into your app instantly.

Get your apps ready

Android 7.1 is an incremental release, but it’s always important to make sure your apps look and run great — especially as devices start to reach consumers.

The Android 7.1 Developer Preview will give you everything you need to test your apps or extend them with new features like shortcuts or keyboard images. Included are the SDK with new APIs, build tools, documentation and samples, as well as emulators and device system images for running your apps on supported Nexus devices. We’ll also include a launcher and apps that support app shortcuts, and a keyboard and apps that support keyboard images.

If you want to receive the Developer Preview automatically, visit Android Beta and enroll your device. If you previously enrolled a device and haven’t unenrolled, your device will receive the update. If you already enrolled but don’t want to receive the update, visit Android Beta to unenroll the device as soon as possible.

Initially, we’ll offer the Developer Preview for Nexus 5X, Nexus 6P, and Pixel C devices, extending to other supported devices by the end of the preview. At the final release of the Android 7.1.x platform, due in early December, we’ll roll out updates to the full lineup of supported devices — Nexus 6, 5X, 6P, 9, Player, Pixel C, and supported Android One devices — as well as Pixel and Pixel XL devices.

Coming to consumer devices soon

We’re working with our partners to bring Android 7.1 to devices in the ecosystem over the months ahead, so we recommend downloading the Android 7.1 Developer Preview as soon as it’s available. Test your apps for compatibility and optimize them to look their best, such as by providing circular app icons and adding app shortcuts.

Meanwhile, stay tuned, we’ll be sharing more details about the Developer Preview soon!

Taking the final wrapper off of Android 7.0 Nougat

Posted by Dave Burke, VP of Engineering
Android Nougat

Android 7.0 Nougat

Today, Android 7.0 Nougat will begin rolling out to users, starting with Nexus devices. At the same time, we’re pushing the Android 7.0 source code to the Android Open Source Project (AOSP), extending public availability of this new version of Android to the broader ecosystem.

We’ve been working together with you over the past several months to get your feedback on this release, and also to make sure your apps are ready for the users who will run them on Nougat devices.

What’s inside Nougat

Android Nougat reflects input from thousands of fans and developers like you, all around the world. There are over 250 major features in Android Nougat, including VR Mode in Android. We’ve worked at all levels of the Android stack in Nougat — from how the operating system reads sensor data to how it sends pixels to the display — to make it especially built to provide high quality mobile VR experiences.

Plus, Nougat brings a number of new features to help make Android more powerful, more productive and more secure. It introduces a brand new JIT/AOT compiler to improve software performance, make app installs faster, and take up less storage. It also adds platform support for Vulkan, a low-overhead, cross-platform API for high-performance, 3D graphics. Multi-Window support lets users run two apps at the same time, and Direct Reply so users can reply directly to notifications without having to open the app. As always, Android is built with powerful layers of security and encryption to keep your private data private, so Nougat brings new features like File-based encryption, seamless updates, and Direct Boot.

You can find all of the Nougat developer resources here, including details on behavior changes and new features you can use in your apps. An overview of what's new for developers is available here, and you can explore all of the new user features in Nougat here.

Multi-window mode in Android Nougat

Multi-window mode in Android Nougat

The next wave of users

Starting today and rolling out over the next several weeks, the Nexus 6, Nexus 5X, Nexus 6P, Nexus 9, Nexus Player, Pixel C, and General Mobile 4G (Android One) will get an over-the-air software update to Android 7.0 Nougat. Devices enrolled in the Android Beta Program will also receive this final version.

And there are many tasty devices coming from our partners running Android Nougat, including the upcoming LG V20, which will be the first new smartphone that ships with Android Nougat, right out of the box.

With all of these new devices beginning to run Nougat, now is the time to publish your app updates to Google Play. We recommend compiling against, and ideally targeting, API 24. If you’re still testing some last minute changes, a great strategy to do this is using Google Play’s beta testing feature to get early feedback from a small group of users — including those using Android 7.0 Nougat — and then doing a staged rollout as you release the updated app to all users.

What’s next for Nougat?

We’re moving Nougat into a new regular maintenance schedule over the coming quarters. In fact, we’ve already started work on the first Nougat maintenance release, that will bring continued refinements and polish, and we’re planning to bring that to you this fall as a developer preview. Stay tuned!

We’ll be closing open bugs logged against Developer Preview builds soon, but please keep the feedback coming! If you still see an issue that you filed in the preview tracker, just file a new issue against Android 7.0 in the AOSP issue tracker.

Thanks for being part of the preview, which we shared earlier this year with an eye towards giving everyone the opportunity to make the next release of Android stronger. Your continued feedback has been extremely beneficial in shaping this final release, not just for users, but for the entire Android ecosystem.

Android N APIs are now final, get your apps ready for Android N!

Posted by Dave Burke, VP of Engineering

As we put the finishing touches on the next release of Android, which will begin to roll out to consumers later this summer, we’re releasing the 4th Developer Preview of Android N, including the Android N final SDK. And thanks to your continued feedback over the last three releases, all of the APIs are now final as well. If you’ve already enrolled your device in the Android Beta Program, (available at android.com/beta) you will receive an update to this Developer Preview shortly.

Get your apps ready for Android N

The final SDK for Android N is now available for download through the SDK Manager in Android Studio. It gives you everything you need to develop and test against the official APIs in the Android N platform. Once you’ve installed the final SDK, you can update your project’s compileSdkVersion to API 24 to develop with the Android N APIs and build and test on the new platform, for new features such as Multi-window support, direct-reply notifications, and others. We also recommend updating your app’s targetSdkVersion to API 24 to opt-in and test your app with Android N specific behavior changes. For details on how to setup your app with the final SDK, see Set up the Preview. For details on API level 24 check out the API diffs and the updated API reference, now hosted online.

Along with the Android N final SDK, we’ve also updated the Android Support Library to 24.0.0. This allows you to use multi-window and picture-in-picture callbacks, new notification features, methods for supporting Direct Boot, and new MediaBrowser APIs in a backward compatible manner.

Publish your apps to alpha, beta or production channels in Google Play

Now that you have a final set of APIs, you can publish updates compiling with, and optionally targeting, API 24 to Google Play. You can now publish app updates that use API 24 to your alpha, beta, or even production channels in the Google Play Developer Console. In this way, you can test your app’s backward-compatibility and push updates to users whose devices are running Developer Preview 4.

To make sure that your updated app runs well on Android N, as well as older versions, a common strategy is to use Google Play’s beta testing feature to get early feedback from a small group of users -- including developer preview users — and then do a staged rollout as you release the updated app to all users.

How to Get Developer Preview 4

Developer Preview 4 includes updated system images for all supported Preview devices as well as for the Android emulator. If you are already enrolled in the Android Beta program, your devices will get the Developer Preview 4 update right away, no action is needed on your part. If you aren’t yet enrolled in Android Beta, the easiest way to get started is by visiting android.com/beta and opt-in your eligible Android phone or tablet -- you’ll soon receive this (and later) preview updates over-the-air. As always, you can also download and flash this update manually. The N Developer Preview is available for Nexus 6, Nexus 5X, Nexus 6P, Nexus 9, and Pixel C devices, as well as General Mobile 4G [Android One] devices and the Sony Xperia Z3.

Thanks so much for all of your feedback so far. Please continue to share feedback or requests either in the N Developer Preview issue tracker, N Preview Developer community, or Android Beta community as we work towards the consumer release later this summer. We’re looking forward to seeing your apps on Android N!

Android 6.0 Marshmallow coming to devices soon

Posted by, Dave Burke, VP of Engineering, Android

Starting next week, Android 6.0 Marshmallow will begin rolling out to supported Nexus devices around the world, including Nexus 5, Nexus 6, Nexus 7 (2013), Nexus 9, Nexus Player, and Android One. At the same time, we’ll be pushing the Android 6.0 source to the Android Open Source Project (AOSP), which marks the official beginning of public availability.

Today we also introduced two great new Nexus devices that will be among the first to run the Android 6.0 Marshmallow platform. These devices let your apps use the latest platform features and take advantage of the latest hardware optimizations from our partners. Let’s take a look at how to make sure your apps look great on these new devices.

Introducing Nexus 5X and Nexus 6P

Nexus 5X
Nexus 6P

The Nexus 5X is built in partnership with LG. It’s equipped with a 5.2-inch FHD LCD 1080p display, a Snapdragon™ 808 processor (1.8 GHz hexa-core, 64-bit), and a 12.3 MP rear camera. Offering top-line performance in a compact, lightweight device.

The Nexus 6P, built in partnership with Huawei, has a 5.7-inch WQHD AMOLED display, Snapdragon™ 810 v2.1 processor (2.0 GHz octa-core 64-bit), front-facing stereo speakers, and a 12.3 MP rear camera, all housed in a diamond-cut aluminum body.

Both devices have USB Type-C ports and fingerprint sensors, and include the latest hardware features for Android, such as: Android Sensor Hub, low-power Wi-Fi scanning with channel selection, batching, and BSSID hotlists, Bluetooth 4.2 with ultra low-power BLE notifications, and more.

Get your apps ready

Take some time to make sure your apps and games are ready to give your users the best mobile experience on these devices.

Check your assets

Resolution Screen size Density
Nexus 5x 1920 x 1080 px (730 x 410 dp) normal 420 dpi
Nexus 6P 2560 x 1440 px (730 x 410 dp) normal 560 dpi

Nexus 5X has a quantized density of 420 dpi, which falls in between the xhdpi and xxhdpi primary density buckets. Nexus 6P has a density of 560 dpi, which falls in between the xxhdpi and xxxhdpi buckets. The platform will scale down any assets from a higher resolution bucket, but if those aren’t available, then it will scale up the assets from a lower-density bucket.

For best appearance in the launcher, we recommend that you provide at least an xxxhdpi app icon because devices can display large app icons on the launcher.

For the rest of your assets, you can consider using vector assets or optionally add versions for the next-higher density bucket. This provides a sharper visual experience, but does increase apk size, so you should make an appropriate decision for your app.

Make sure you are not filtered on Google Play

If you are using the <compatible-screens>: element in your AndroidManifest.xml file, you should stop using it because it’s not scalable to re-compile and publish your app each time new devices come out. If you must use it, make sure to update your manifest to add a new configuration for Nexus 5X, since it uses a new density bucket (420). Otherwise, your app may be filtered from Google Play on these devices.

Wrapping up M Developer Preview

After three preview releases, and with the final OTA coming soon, it’s time to wrap up the Android M Developer Preview. The feedback you’ve provided has helped make Android 6.0 a great platform for apps and games. Developers in more than 200 countries have been using the Developer Preview to get their apps ready for Android 6.0 Marshmallow users everywhere.

More developer resources

If you haven’t taken a look at Android 6.0 Marshmallow yet, visit developer.android.com/mm for complete information about about what’s new for developers and important changes to plan for in your apps — runtime permissions, Doze and App Standby idle modes, Auto Backup for Apps, fingerprint support, and others.

We’ve also produced a playlist of developer videos to help you get the most out of all the new features in Android 6.0 Marshmallow. Check it out below.

Final testing and updates

Now is the time to finish up testing and prepare for publishing. You can use the Developer Preview 3 system images for final testing until early October. After the Android 6.0 public release, you’ll be able to download final images from the Nexus factory images page, and final emulator images from Android Studio.

Reminder: Devices flashed with an M Developer Preview build won’t receive the Android 6.0 update automatically. You’ll need to manually flash those devices to a public released image first.

Upload your apps to Google Play

When your apps are ready, you can update them to Google Play via the Developer Console on all release channels (Alpha, Beta & Production). For apps that target API level 23, Google Play will provide the new optimized download and autoupdate flow based on the runtime permissions model in Android 6.0. Give it a try!

To make sure that your updated app runs well on Android 6.0 Marshmallow and older versions, we recommend that you use the newly improved beta testing feature on Google Play to get early feedback. You can then do a staged rollout as you release the new version to all users.

What’s next?

In mid-October, we’ll be turning down the M Developer Preview community and the M Developer Preview issue tracker. If the you filed bugs against the preview that you want to leave open against the Android 6.0 final builds, you can file a new issue in the AOSP issue tracker.

Thanks to everyone who participated in the Android M Developer Preview. Let us know how this year’s preview met your needs by taking a short survey. Your feedback helps shape our future releases.


Develop a sweet spot for Marshmallow: Official Android 6.0 SDK & Final M Preview

By Jamal Eason, Product Manager, Android

Android 6.0 Marshmallow

Whether you like them straight out of the bag, roasted to a golden brown exterior with a molten center, or in fluff form, who doesn’t like marshmallows? We definitely like them! Since the launch of the M Developer Preview at Google I/O in May, we’ve enjoyed all of your participation and feedback. Today with the final Developer Preview update, we're introducing the official Android 6.0 SDK and opening Google Play for publishing your apps that target the new API level 23 in Android Marshmallow.

Get your apps ready for Android Marshmallow

The final Android 6.0 SDK is now available to download via the SDK Manager in Android Studio. With the Android 6.0 SDK you have access to the final Android APIs and the latest build tools so that you can target API 23. Once you have downloaded the Android 6.0 SDK into Android Studio, update your app project compileSdkVersion to 23 and you are ready to test your app with the new platform. You can also update your app to targetSdkVersion to 23 test out API 23 specific features like auto-backup and app permissions.

Along with the Android 6.0 SDK, we also updated the Android Support Library to v23. The new Android Support library makes it easier to integrate many of the new platform APIs, such as permissions and fingerprint support, in a backwards-compatible manner. This release contains a number of new support libraries including: customtabs, percent, recommendation, preference-v7, preference-v14, and preference-leanback-v17.

Check your App Permissions

Along with the new platform features like fingerprint support and Doze power saving mode, Android Marshmallow features a new permissions model that streamlines the app install and update process. To give users this flexibility and to make sure your app behaves as expected when an Android Marshmallow user disables a specific permission, it’s important that you update your app to target API 23, and test the app thoroughly with Android Marshmallow users.

How to Get the Update

The Android emulator system images and developer preview system images have been updated for supported Nexus devices (Nexus 5, Nexus 6, Nexus 9 & Nexus Player) to help with your testing. You can download the device system images from the developer preview site. Also, similar to the previous developer update, supported Nexus devices will receive an Over-the-Air (OTA) update over the next couple days.

Although the Android 6.0 SDK is final, the devices system images are still developer preview versions. The preview images are near final but they are not intended for consumer use. Remember that when Android 6.0 Marshmallow launches to the public later this fall, you'll need to manually re-flash your device to a factory image to continue to receive consumer OTA updates for your Nexus device.

What is New

Compared to the previous developer preview update, you will find this final API update fairly incremental. You can check out all the API differences here, but a few of the changes since the last developer update include:

  • Android Platform Change:
  • Final Permissions User Interface — we updated the permissions user interface and enhanced some of the permissions behavior.
  • API Change:
  • Updates to the Fingerprint API — which enables better error reporting, better fingerprint enrollment experience, plus enumeration support for greater reliability.

Upload your Android Marshmallow apps to Google Play

Google Play is now ready to accept your API 23 apps via the Google Play Developer Console on all release channels (Alpha, Beta & Production). At the consumer launch this fall, the Google Play store will also be updated so that the app install and update process supports the new permissions model for apps using API 23.

To make sure that your updated app runs well on Android Marshmallow and older versions, we recommend that you use Google Play’s newly improved beta testing feature to get early feedback, then do a staged rollout as you release the new version to all users.

Enable your messaging app for Android Auto

Posted by Joshua Gordon, Developer Advocate

What if there was a way for drivers to stay connected using your messaging app, while keeping their hands on the wheel and eyes on the road?

Android Auto helps drivers stay connected, but in a more convenient way that's integrated with the car. It eliminates the need to type and read messages by replacing these activities with a voice controlled interface.

Enabling your messaging app to work with Android Auto is easy. Developers like Skype and textPlus have already done so. Check out this DevByte for an overview of the messaging APIs, and see the developer training guide for a deep dive. Read on for a look at the key steps involved.


Message notifications on the car’s display

When an Android 5.0+ phone is connected to a compatible car, users receive incoming message notifications from Auto-enabled apps on the car’s head unit display. Your app runs on the phone, but is controlled by the car. To learn more about how this works, watch the Introduction to Android Auto DevByte.

A new message notification from Skype

If your app already uses notifications to alert the user to incoming messages, it’ll be easy to extend these for Auto. It takes just a few lines of code, and you won’t have to change how your app works on the phone.

There are a couple small differences between message notifications on Auto vs. a phone. On Auto, a preview of the message content isn’t shown, because messaging is driven entirely by voice. Second, message notifications are backed by a conversation object. This is simply a collection of unread messages from a particular sender.

Decorate your notification with the CarExtender to add support for the car. Next, use the UnreadConversation.Builder to create a conversation, and populate it by iterating over your app's unread messages (from a certain sender) and adding them to the conversation. Pass your conversation object to the CarExtender, and you’re done!

Tap to hear messages

Tapping on a message notification plays it back on the car's sound system, via text to speech. This is handled automatically by the framework; no additional code is required. Pretty cool, right?

In order to know when the user hears a message, you provide a PendingIntent that’s triggered by the system. That’s one of just two intents you’ll need to handle to enable your app for Auto.

Reply by voice

Voice control is the real magic of Android Auto. Users reply to messages by speaking, via voice recognition. This is far faster and more natural than typing.

Enabling this functionality is as simple as adding a RemoteInput instance to your conversation objects, before you issue the notification. Speech recognition is handled entirely by the framework. The recognition result is delivered to your app as a plain text string via a second PendingIntent.

Replying to a message from textPlus by voice.

Next Steps

Make your messaging app more natural to use in the car by enabling it for Android Auto. Now drivers can stay connected, without typing or reading messages. It just takes a few lines of code. To learn more visit developer.android.com/auto

Power Great Gaming with New Analytics from Play Games

By Ben Frenkel, Google Play Games team

A few weeks ago at the Game Developers Conference (GDC), we announced Play Games Player Analytics, a new set of free reports to help you manage your games business and understand in-game player behavior. Today, we’re excited to make these new tools available to you in the Google Play Developer Console.

Analytics is a key component of running a game as a service, which is increasingly becoming a necessity for running a successful mobile gaming business. When you take a closer look at large developers that do this successfully, you find that they do three things really well:

  • Manage their business to revenue targets
  • Identify hot spots in their business metrics so they can continuously focus on the game updates that will drive the most impact
  • Use analytics to understand how players are progressing, spending, and churning

“With player engagement and revenue data living under one roof, developers get a level of data quality that is simply not available to smaller teams without dedicated staff. As the tools evolve, I think Google Play Games Player Analytics will finally allow indie devs to confidently make data-driven changes that actually improve revenue.”

Kevin Pazirandeh
Developer of Zombie Highway 2

With Player Analytics, we wanted to make these capabilities available to the entire developer ecosystem on Google Play in a frictionless, easy-to-use way, freeing up your precious time to create great gaming experiences. Small studios, including the makers of Zombie Highway 2 and Bombsquad, have already started to see the benefits and impact of Player Analytics on their business.

Further, if you integrate with Google Play game services, you get this set of analytics with no incremental effort. But, for a little extra work, you can also unlock another set of high impact reports by integrating Google Play game services Events, starting with the Sources and Sinks report, a report to help you balance your in-game economy.

If you already have a game integrated with Google Play game services, go check out the new reports in the Google Play Developer Console today. For everyone else, enabling Player Analytics is as simple as adding a handful of lines of code to your game to integrate Google Play game services.

Manage your business to revenue targets

Set your spend target in Player Analytics by choosing a daily goal

To help assess the health of your games business, Player Analytics enables you to select a daily in-app purchase revenue target and then assess how you're doing against that goal through the Target vs Actual report depicted below. Learn more.

Identify hot spots using benchmarks with the Business Drivers report

Ever wonder how your game’s performance stacks up against other games? Player Analytics tells you exactly how well you are doing compared to similar games in your category.

Metrics highlighted in red are below the benchmark. Arrows indicate whether a metric is trending up or down, and any cell with the icon can be clicked to see more details about the underlying drivers of the change. Learn more.

Track player retention by new user cohort

In the Retention report, you can see the percentage of players that continued to play your game on the following seven days after installing your game.

Learn more.

See where players are spending their time, struggling, and churning with the Player Progression report

Measured by the number of achievements players have earned, the Player Progression funnel helps you identify where your players are struggling and churning to help you refine your game and, ultimately, improve retention. Add more achievements to make progression tracking more precise.

Learn more.

Manage your in-game economy with the Sources and Sinks report

The Sources and Sinks report helps you balance your in-game economy by showing the relationship between how quickly players are earning or buying and using resources.

For example, Eric Froemling, one man developer of BombSquad, used the Sources & Sinks report to help balance the rate at which players earned and spent tickets.

Read more about Eric’s experience with Player Analytics in his recent blog post.

To enable the Sources and Sinks report you will need to create and integrate Play game services Events that track sources of premium currency (e.g., gold coins earned), and sinks of premium currency (e.g., gold coins spent to buy in-app items).

Game Performance: Layout Qualifiers

Today, we want to share some best practices on using the OpenGL Shading Language (GLSL) that can optimize the performance of your game and simplify your workflow. Specifically, Layout qualifiers make your code more deterministic and increase performance by reducing your work.

Let’s start with a simple vertex shader and change it as we go along.

This basic vertex shader takes position and texture coordinates, transforms the position and outputs the data to the fragment shader:
attribute vec4 vertexPosition;
attribute vec2 vertexUV;

uniform mat4 matWorldViewProjection;

varying vec2 outTexCoord;

void main()
{
  outTexCoord = vertexUV;
  gl_Position = matWorldViewProjection * vertexPosition;
}

Vertex Attribute Index

To draw a mesh on to the screen, you need to create a vertex buffer and fill it with vertex data, including positions and texture coordinates for this example.

In our sample shader, the vertex data may be laid out like this:
struct Vertex
{
  Vector4 Position;
  Vector2 TexCoords;
};
Therefore, we defined our vertex shader attributes like this:
attribute vec4 vertexPosition;
attribute vec2  vertexUV;
To associate the vertex data with the shader attributes, a call to glGetAttribLocation will get the handle of the named attribute. The attribute format is then detailed with a call to glVertexAttribPointer.
GLint handleVertexPos = glGetAttribLocation( myShaderProgram, "vertexPosition" );
glVertexAttribPointer( handleVertexPos, 4, GL_FLOAT, GL_FALSE, 0, 0 );

GLint handleVertexUV = glGetAttribLocation( myShaderProgram, "vertexUV" );
glVertexAttribPointer( handleVertexUV, 2, GL_FLOAT, GL_FALSE, 0, 0 );
But you may have multiple shaders with the vertexPosition attribute and calling glGetAttribLocation for every shader is a waste of performance which increases the loading time of your game.

Using layout qualifiers you can change your vertex shader attributes declaration like this:
layout(location = 0) in vec4 vertexPosition;
layout(location = 1) in vec2 vertexUV;
To do so you also need to tell the shader compiler that your shader is aimed at GL ES version 3.1. This is done by adding a version declaration:
#version 300 es
Let’s see how this affects our shader, changes are marked in bold:
#version 300 es

layout(location = 0) in vec4 vertexPosition;
layout(location = 1) in vec2 vertexUV;

uniform mat4 matWorldViewProjection;

out vec2 outTexCoord;

void main()
{
  outTexCoord = vertexUV;
  gl_Position = matWorldViewProjection * vertexPosition;
}
Note that we also changed outTexCoord from varying to out. The varying keyword is deprecated from version 300 es and requires changing for the shader to work.

Note that Vertex Attribute qualifiers and #version 300 es are supported from OpenGL ES 3.0. The desktop equivalent is supported on OpenGL 3.3 and using #version 330.

Now you know your position attributes always at 0 and your texture coordinates will be at 1 and you can now bind your shader format without using glGetAttribLocation:
const int ATTRIB_POS = 0;
const int ATTRIB_UV   = 1;

glVertexAttribPointer( ATTRIB_POS, 4, GL_FLOAT, GL_FALSE, 0, 0 );
glVertexAttribPointer( ATTRIB_UV, 2, GL_FLOAT, GL_FALSE, 0, 0 );
This simple change leads to a cleaner pipeline, simpler code and saved performance during loading time.

To learn more about performance on Android, check out the Android Performance Patterns series.

Posted by Shanee Nishry, Games Developer Advocate