Google released the SDK for Android 4.2 yesterday, and developers are undoubtedly already digging into it. The Android team went over the main features of the SDK proper yesterday, but now it’s time to show off some of the new additions hitting the SDK Tools this time around.

The Android team announced that they’re launching the Android SDK Tools, Revision 21 today alongside 4.2 SDK proper. Much like the new features in the SDK, the new Tools will surely help developers create some stellar Android apps.

Every Android device is different, and as such, developers need to test their UIs across all of these devices. The new SDK Tools comes with a multi-config editor for that very reason. Developers can now prototype UIs across various orientations, screen sizes and locales. It also lets developers see how embedded layouts will look inside of larger layouts.

Another addition to the UI tools in the latest release is the UI Automator Test Framework. As its name suggests, it allows developers to automate UI testing. It saves a lot of time that used to be wasted with manual UI testing. The UI Automator runs on Android 4.1 Developers will want to check out the UI Testing documentation here.

Amateur developers will be pleased to find a number of new SDK Tools tailored towards them. For starters, there’s three new app templates for developers to easily add new screens to their app. The three new templates include a full-screen video/photo viewer, settings for basic user preferences, and a login screen.

The other addition for beginner developers is a one-click SDK installer. To save time and cut down on headaches, developers can download all of the various SDK components with a single click. Existing developers can still manager SDK components separately as they always have.

Google has also introduced a new AVD creation dialog. Now it’s easier than ever to to create virtual devices that match real Android device profiles. Google says that these new AVDs will also show up in the layout editor so that you know how the layouts will look on each device.

Lastly, there are 25 new Lint rules that will help catch common sources of bugs in Android apps. For example, Google says that the new rules cover deviations from the Android design guide for icons, mismanaged wakelocks and more.

For more information on the new SDK Tools, check out Google’s documentation.