Not all that long ago, Android Studio 2.1 was released in an unfinished beta form, missing a few features and having many others either partially implemented or not terribly well-polished. Android Studio 2.0, meanwhile, was released officially and brought a plethora of new features with it, like a better emulator and instant run code-checking, but has already been surpassed by Tuesday's announcement of Android Studio 2.1 dropping officially. The newest version of Android Studio brings a number of refinements to old features, and a few new ones. The big headliner feature, however, is support for the newest version of Android, the Android N developer preview, which is still only officially available to the Nexus lineup and the Sony Xperia Z3, though the Xperia Z2 and some other devices have gotten unofficial ports.
For starters, the Instant Run feature from Android Studio 2.0 is here to stay and has gotten a few tweaks and bits of polish here and there. Incremental compilation of Java code and in-process dex file management are on board to help make instant implementation and testing of new bits of code just a little bit smoother. This means that developers can check out a snippet of Java code and modify it as needed, even inserting it replace existing code in-place. Dex file management, meanwhile, gains the ability to convert class files to dex inside the Gradle daemon for quicker in-place conversion and testing. Mind you, this feature requires at least 2GB of RAM to be allocated to the Gradle daemon, so developers on older hardware may want to be careful.
The new build of Android Studio 2.1 comes complete with all of the API calls and language tweaks present in the Android N developer preview, including the brand new Jack compiler and support for Java 8. Support will be enabled by default for new projects and can be enabled in existing projects with a few settings tweaks. Naturally, this means that Android Virtual Devices made and used in the Studio, as well as the Android Emulator, can be set to act like Android N, allowing testing of cross-compatible apps in order to prevent boxing out Marshmallow and legacy users for the sake of N support.