Google has released the first developer preview of Wear OS 5.1, based on Android 15, for testing in the Android Studio emulator. Key features include audio playback through smartwatch speakers and the new Credential Manager API. The build number for this preview is AP4A.241205.004.F1. Known issues include difficulties in adding accounts during setup, notifications not opening corresponding apps until the screen is scrolled, and potential failures in initiating exercise sessions with Wear Health Services. The audio feature allows users to listen to music or podcasts from the smartwatch's speaker, while the Credential Manager API supports password management and synchronization across devices.