Tools and libraries to help your Wear OS app satisfy Google Play app quality requirements
As of August 31, 2023, all apps that support Wear OS must meet Wear OS app quality requirements in order to be published on the Google Play Store.
This blog post walks you through available tools and libraries — including the Horologist library, the Wear OS emulator in Android Studio, and adaptive icons — to help you more easily meet some of these requirements.
Horologist libraries
Horologist is an open source project, built on top of Jetpack Compose, which helps developers accelerate app development. We recommend adopting Horologist to facilitate compliance with the following Google Play Store requirements.
Show a scrollbar
When a screen is scrollable, a scrollbar should appear because this indicates to users that there is more content on the screen.
Use Horologist’s ScreenScaffold to automatically add a position indicator to your app’s scrollable screens and make the scrollbar visible when the user is scrolling. Additionally, use AppScaffold from Horologist to preserve the scroll position when navigating between screens and animate the TimeText element when moving between pages.
See an example on how to use Horologist ScreenScaffold and Horologist AppScaffold in the Wear OS sample on GitHub.
Watch shapes
A Wear OS app should display the entire contents of visual elements; text and controls shouldn’t be cut off by the screen edges.
To make sure elements at the top and the bottom of the screen are fully visible, use the Horologist rememberResponsiveColumnState() with a ScalingLazyColumn, as shown in the example below:
Additionally, the rememberResponsiveColumnState() handles the rotary input automatically.
For a full example, see the ComposeStarter sample on Github.
Wear OS emulator in Android Studio
The Wear OS emulator, available in Android Studio, is helpful both during the development of your app and as a tool for testing. Use the emulator to help your app meet the following requirements.
Play listing compatible screenshots
Starting from the Android Studio Hedgehog release, the Wear OS emulator lets you take Play listing compatible screenshots. These screenshots don’t include any masking, such as device images, and use a black background.
You can generate Play compatible screenshots by completing these steps:
1) Start an instance of the emulator.
2) Take a screenshot.
3) In the drop-down menu near the top of the screenshot preview, select the “Play Store compatible” option:
User-configured font size
Your text content should scale correctly when a user changes the text size in the watch settings. Similar to the watch shapes requirements, when the user changes text sizes, your app’s visual elements shouldn’t overlap, or be cut off on the screen edges. By adopting Horologist responsive components, such as rememberResponsiveColumnState(), you can make sure your components are responsive.
You can use the emulator to visually verify that your app’s content behaves as expected. To select a different text size, go to Settings > Accessibility > Text Size and select different sizes, as shown from the emulator screenshot below. Additionally, you should test your app’s content scaling behavior on different display sizes. The emulator supports several display sizes, including Wear OS Small Round (192x192dp) and Wear OS Large Round (227x227dp).
In addition to performing manual visual checks (which you can achieve by using Compose Previews), add automated screenshot testing to catch regressions on different resolutions. See an example in Wear OS samples tests, which uses Roborazzi to implement screenshot testing.
Lastly, stay tuned for the new screenshot testing preview tool, introduced at #TheAndroidShow (minute 8:53) and described in more detail at DroidCon London. This tool is coming soon to Android Studio.
Splash screen
Starting in Wear OS 4, the system automatically shows the app icon as the splash screen icon, unless your app uses a custom theme and needs to keep the splash screen on-screen for longer periods. If you’re using a custom theme, migrate to the SplashScreen API.
Adaptive icons, introduced in Android 8.0, let developers provide icons that adapt to various screen shapes and sizes. By using Adaptive icons, you can more easily meet the splash screen quality guideline, which requires that your app’s splash screen icon must be a round icon and match the icon shown in the list of apps on a Wear OS device.
See a full working example in the Wear OS sample on GitHub.
Wrap up
In this blogpost, we reviewed how different tools and libraries — including the Horologist project, Wear OS emulator in Android Studio, and adaptive icons — can help you meet the Wear OS app quality requirements, including:
- Showing a scrollbar on scrollable screens
- Displaying content on different watch display sizes
- Generating Play listing compatible screenshots
- Scaling text when the user configures the text size
- Loading the correct icon in your app’s splash screen
For more developer and design guidance visit d.android.com/wear. We look forward to seeing the fantastic experiences you create next in your Wear OS app!
