Android 17 QPR2 Beta 3 introduces a native App Lock feature for Pixel devices, allowing users to secure applications by long-pressing them and selecting the App Lock option from the Actions menu. Accessing locked applications requires authentication via Fingerprint Unlock or PIN. Key points include that notification content will be concealed when an app is locked, widgets and shortcuts for the locked app will be removed from the home screen, and AI agents with access to the app can still access its data. Users can manage app security settings through Settings > Security & privacy > App lock. The update is scheduled for rollout in December.