Test your app for compatibility

Wear OS 4 Developer Preview is based on Android 13 (API level 33), which is several versions newer than the version on which Wear OS 3 is based, Android 11 (API level 30). So when you prepare your Wear OS app for use on Wear OS 4 Developer Preview, you need to handle the system behavior changes that took effect for all apps in Android 12 and Android 13, as well as the changes that took effect for apps that target Android 12 and target Android 13.

The following changes are most likely to affect your Wear OS app:

Changes to notifications and ongoing activities

The OngoingActivity class is based on the OngoingNotification class, so ongoing activities are affected by the notification runtime permission changes introduced in Wear OS 4 Developer Preview. Some notifications are exempt, such as those related to media sessions.

Changes to background body sensor permission

Wear OS 4 Developer Preview introduces a new way for apps to access body sensors, such as heart rate, temperature, and blood oxygen percentage, in the background. Learn more in the guide to background body sensor permission changes.

System alert window UI is removed

Wear OS 4 Developer Preview removes the system UI for granting the SYSTEM_ALERT_WINDOW permission. This UI is available on some devices that run Wear OS 3 and lower.

If you use ACTION_MANAGE_OVERLAY_PERMISSION to send users to a settings page, where they could display your app over other apps, update your app's logic. For example, if you rely on system alert windows to show important messages, use notifications instead.