What you need for this book
Developing Android applications requires the Android SDK, available on multiple platforms, including Windows, Mac, and Linux.
Though not required, this book uses Android Studio, the official Android IDE. If you are new to Android development, visit the following link to review the current system requirements and download Android Studio with the SDK bundle for your platform:
http://developer.android.com/sdk/index.html
The Android SDK and Android Studio are both free of charge.