Google Android rocks at how fast they push out fixes with the updates !!! Full SDK for Android 4.1 is now available!, SDK Tools r 20.0.1 update! . Developers have been able to play with the Android 4.1 Jelly Bean software developers kit (SDK) since it was first launched at Google I/O, but the company announced that the full software developers kit (SDK) for Android 4.1 Jelly Bean is now available to developers and can be downloaded through Google’s developer portal. also SDK Tools revision 20.0.1 released with bug fixes to several annoying bugs .
Google’s developer portal:
“We are pleased to announce that the full SDK for Android 4.1 is now available to developers and can be downloaded through your SDK Manager. You can now develop and publish applications against API level 16 using new Jelly Bean APIs. We are also releasing SDK Tools revision 20.0.1 and NDK revision 8b containing bug fixes only”
Google encourages developers to use the Nexus 7 as their base for creating good app experiences, and says that developers should “keep up” with the example set by the Nexus 7′s native apps with respect to performance and appearance.
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For a summary of all known issues in SDK Tools, see http://tools.android.com/knownissues.
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Android Developers
We’re pleased to announce that the full SDK for Android 4.1 is now available to developers and can be downloaded through your SDK Manager.
To celebrate, +Nick Butcher has sharedsome tips for optimizing your application to make the most of the new SDK and optimize your apps for Nexus 7.
(We’re also releasing SDK Tools revision 20.0.1 and NDK revision 8b containing bug fixes only)
Tor Norbye (Google):
If you’re using ADT 20 you should definitely update; this fixes several annoying bugs. However, it doesn’t include the fix for the Juno/Eclipse4 keybindings issue (which was integrated a few hours ago), so you might want to use Eclipse 3.7.2 for now. Or use a daily ADT build 
See issue http://code.google.com/p/android/issues/detail?id=34630 for details. We’ll hopefully put out another maintenance release for this soon.
Xavier Ducrohet(Google):
Update of the Android Tools to 20.0.1 is live.
Lots of bug fixes in both the tools package and in the Eclipse plugin.
Release notes: http://developer.android.com/tools/sdk/tools-notes.htmland http://developer.android.com/tools/sdk/eclipse-adt.html
Also download the new system image and the new platform components for API 16. The latter one fixes the rendering problem in Eclipse.
About SDK Tools, Revision 20.0.1 :
Dependencies:
- Android SDK Platform-tools revision 12 or later.
- If you are developing in Eclipse with ADT, note that the SDK Tools r20.0.1 is designed for use with ADT 20.0.1 and later. If you haven’t already, update your ADT Plugin to 20.0.1.
- If you are developing outside Eclipse, you must have Apache Ant 1.8 or later.
Bug fixes:
- Fixed wrong check on build state that forced repetitive Java code recompilation.
- Fixed problems with running more than one emulator and running multiple emulators with GPU acceleration.
- Improved resize algorithm for better rendering on scaled emulator windows.
- Fixed a bug in the lint check for unprotected broadcast receivers to ignore unprotected receivers for default Android actions.
- Fixed build issue for projects using Renderscript.
- Fixed memory leak in the emulator.
Bugs I Found in ADT 20 !:
Google always they are very quick to respond the bug! and how fast they push out fixes! here is the example.
When I updated my SDK to new android sdk tools r20, I’m not able to run more than one emulator!! I simply put that issues in code.google.com look at here how I got the quick response and fix in the new SDK Tools, r 20.0.1!
Issue!!:
Fixed!:
More info about Fixed Bug click me!
Android Developer rocks !! how fast they push out fixes! Awesome!!.