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.

Android is the prime OS for developing applications in today for many reasons. The main reasons being that it is Open Source and Intuitive. In addition it uses Java for development, which is quite … ...

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.