The 4th and final developer preview of the next version of Android, named Android N has been released. Devices which has been enrolled to the Android beta program will be notified of an update to the Developer Preview Version.
You can download the final SDK from the SDK Manager in Android Studio. With this, you will be able to test your app against the official Android N APIs. You can test for new features such as Multi-window, direct reply and more.
The Android support library has been updated to 24.0.0, allowing you to use multi-window, picture in picture callbacks, new notification features, new MediaBrowser APIs and methods for supporting Direct Boot.
The N Developer Preview is now available for Nexus 6, Nexus 5X, Nexus 6P, Nexus 9, and Pixel C devices, as well as General Mobile 4G [Android One] devices and the Sony Xperia Z3.