Android Studio is the official IDE for Android application development, based on IntelliJ IDEA. On top of the capabilities you expect from IntelliJ, Android Studio offers:

Flexible Gradle-based build system
Build variants and multiple apk file generation
Code templates to help you build common app features
Rich layout editor with support for drag and drop theme editing
Lint tools to catch performance, usability, version compatibility, and other problems
ProGuard and app-signing capabilities
Built-in support for Google Cloud Platform, making it easy to integrate Google Cloud Messaging and App Engine
And much more