Have you ever wanted to create your own Android app? Whether you're a beginner or someone looking to enhance your mobile ...

To fix that, you have to open the SDK Manager, deselect the ‘Hide obsolete packages’ option on the bottom-right corner, and further, install the Android SDK Tools (obsolete) folder.

Android development starts with the Android SDK - a collection of tools needed to build any kind of Android app. Discover what's included and how to use it.

The Android R Preview SDK just appeared in the SDK Manager, meaning there's likely some new stuff to poke through. As you can see from the screenshot above, Android R revision 1 is now in the list.