Important changes in Android N Developer Preview 3 (NPD35K) include VR Mode for Android, Sustained performance mode, Multiprocess WebView, etc. and bug fixes include Bluetooth audio playback interruption, Bluetooth keeps disconnecting, clock and toast notification issues, multi-window mode issue, etc.
New in Android N Developer Preview 3 (NPD35K) You can see all the new changes, bug fixes and features of Android N Developer Preview 3 (NPD35K) update at this page. Sustained Performance Mode: Android N includes optional support for sustained performance mode, enabling OEMs to provide hints on device performance capabilities for long running applications. Only on Nexus 6P at the moment. Multiprocess WebView: Starting with version 51 in Android N, WebView will run web content in a separate sandboxed process when the developer option “Multiprocess WebView” is enabled. Download and Installation If you have opted for Android Beta program, you will get the OTA (over the air) for the new update. New users can download the Android N DP3 factory image [HERE] and flash it manually. (Source)