Основные руководящие принципы качества приложения

Display orientations and fold states expose essentially the same features and actions and preserve functional parity.

App fills the app window in both orientations and is not letterboxed because of configuration changes, including device folding and unfolding.

Minor letterboxing to compensate for small variations in screen geometry is acceptable.

App displays graphics, text, images, and other UI elements without noticeable distortion, blurring, or pixelation.

• App uses vector drawables where possible
• App uses high-quality graphics for all targeted screen sizes and form factors
• No aliasing at the edges of menus, buttons, and other UI elements

The app preserves user or app state when leaving the foreground and prevents accidental data loss due to back navigation and other state changes.

When returning to the foreground, the app restores the preserved state and any pending stateful transactions. Examples include changes to editable fields, game progress, menus, videos, and other sections of the app.

• When the app is resumed from the Recents app switcher, the app returns the user to the exact state in which the app was last used.
• When the app is resumed after the device wakes from the sleep (locked) state, the app returns the user to the exact state in which the app was last used.
• When the app is relaunched from Home or All Apps, it should do one of the following, depending on how much time has passed since the app was last used:
• If the app was last used a short time ago (minutes), restore the app state as closely as possible to its previous state.
• If more time has passed since the app was last used, try to restore the app as closely as possible to its previous state or start the app from its home screen or some other default state.

Notifications provide relevant information related to your app.

• Don't use notifications for cross-promotion or advertising of another product, as this is strictly prohibited by the Play Store.
• Notification channels are defined according to best practices, rather than serving all notifications from one channel.
• Select the correct notification priority.
• Stack multiple notifications into a single notification group when possible.
• Set timeouts for notifications where appropriate.
• Notifications are persistent only if related to ongoing events, such as music playback or a phone call. For more information, see the Functionality section.

For messaging apps, social apps and conversations:

• Use the MessagingStyle notifications for conversations.
• Support the direct reply action.
• Support conversation shortcuts, and implement best practices for getting the best direct share ranking.
• Support bubbles.

App text and foreground content maintain the following contrast ratios with the app background:

• 3:1 for large text and graphics
• 4.5:1 for small text (less than 18 pt or less than 14 pt if text is bold)

Learn more about color and contrast.

When the user initiates audio playback, the app should do one of the following within one second:

• Start playing the audio
• Provide a visual indicator that the audio data is being prepared

App avoids running unnecessarily long services in the background. To ensure the smooth running of the user's device.

Note: The system applies various restrictions on background services.

The following are poor uses of background services:

• Maintaining a network connection for notifications
• Maintaining a Bluetooth connection
• Keeping the GPS powered on

For more information, see Background tasks overview.

Any Google or third-party SDKs used are up to date. Any improvements to these SDKs related to stability, compatibility, or security should be available to users in a timely manner.

For Google SDKs, use SDKs powered by Google Play services when available. These SDKs are backward compatible, receive automatic updates, reduce your app package size, and make efficient use of on-device resources.

App properly supports power management features Doze and App Standby.

Apps can request a power maintenance exemption. See Support for other use cases in Optimize for Doze and App Standby.

App requests permission to access sensitive data (such as SMS or Call Log permission groups or location) or services that cost money (such as Dialer or SMS) only when directly related to the app's core use cases. Implications related to these permissions must be prominently disclosed to the user.

Depending on how your app uses the permissions, an alternative way of fulfilling your app's use case might be possible without relying on access to sensitive information. For example, instead of requesting permissions related to a user's contacts, use an implicit intent to request access.

App sets the android:exported attribute explicitly for all activities, services, broadcast receivers, and especially content providers.

Only application components that share data with other apps, or components that should be invoked by other apps, are exported.

All intents and broadcasts follow best practices:

• Use explicit intents if the destination application is well defined.
• Use intents to defer permissions to a different app that already has the permission.
• Share data securely across apps.
• Intents that contain a payload are verified before use.
• If you need to pass an intent to another app, so that the receiving app can invoke and expect a callback in the calling app, don't include a nested intent in the extras. Use a PendingIntent.
• When setting up pending intents, explicitly set the immutable flag, where applicable.

All components that share content between apps use android:protectionLevel="signature" for custom permissions. This includes activities, services, broadcast receivers, and especially content providers.

Apps shouldn't rely on accessing a list of installed packages.

Web views don't use addJavaScriptInterface() with untrusted content.

On Android 6.0 (API level 23 and higher), use HTML message channels instead.

App does not dynamically load code from outside the app's APK. Use Android App Bundles, which include Play Feature Delivery and Play Asset Delivery.

As of August 2021, the use of Android App Bundles is mandatory for all new apps in the Google Play Store.

App feature graphic follows the guidelines outlined in this support article. Make sure that:

• App listing includes a high-quality feature graphic
• The feature graphic does not contain device images, screenshots, or small text that's illegible when scaled down and displayed on the smallest screen size that your app is targeting
• The feature graphic does not resemble an advertisement

Navigate to all parts of the app—all screens, dialogs, settings, and all user flows.

Perform core functionality tests with the app installed on a device's SD card (if the app supports this installation method).

To move the app to an SD card, see the app Settings.

From each app screen, rotate the device between landscape and portrait orientations and folded and unfolded states at least three times.

Review all text blocks in the app. Verify that text and text block line length is limited to 45-75 characters (including spaces) for readability.

Navigate to all parts of the app—all screens, dialogs, settings, and all user flows.

From each app screen, press the Back button or use the back swipe gesture. The app should navigate to the previous or home screen.

Use all major features of your app. Verify that no long-running background services are started.

Switch to another app to send your app to the background. Go to Settings and check whether your app has any services running while in the background. On Android 4.0 and higher, go to the Apps screen and find the app in the Running tab.

Enable StrictMode in your app. Use all major features. Verify that the app doesn't produce any StrictMode performance warnings; that is no red flashes are visible when testing the app. Red flashes indicate bad behavior regarding storage, network access, or memory management (such as memory leaks).

Pay close attention to garbage collection and its impact on the user experience.

Use all major app features in Doze and App Standby modes. Verify that alarms, timers, notifications, and syncs function properly in the Doze maintenance window and when the app exits App Standby mode.

Test Doze and App Standby behavior using ADB commands (see Test with Doze and App Standby for requirements and guidelines).

To diagnose unexpected battery drain, use the Android Studio Power Profiler or the Battery Historian tool combined with planned background work.