Android SDK Tools Revision 20.0.1, full SDK for Android 4.1, released. You can now develop and publish applications against API level 16 using new Jelly Bean APIs. The new update can be downloaded through SDK Manager. Also updated are NDK revision 8b and ADT Plugin 20.0.1.
Update SDK on Eclipse:
Please note that note that the SDK Tools r20.0.1 is designed for use with ADT 20.0.1 and later. To update ADT in Eclipse, click Help -> Check for updates, to update ADT.
After updated ADT, click Window -> Android SDK Manager to install updated components.