Best Free Android App Development Sites

List of Android App Development Site:

Google Android:

1.  Google Projects for Android
2.  Android JavaDoc
3.  Offical Android Developers Blog
4.  Android Source
5.  Official Android Development Groups
6.  Android Training
7. Android Kitkat.com 

Android News:

1. Talk Android 
2. Android Authority
3. Android Central
4. The Verge

Android Programming & Development 

1.  Official Google Android Developer’s Guide
2.  Vietnamese Android Community
3.  HelloAndroid
4.  Android Development Community | Android Tutorials
5.  Android Snippets
6.  kAndroid – Android Platform Developer’s Guide
7. Stack Overflow

Android Patterns

1.  Android Patterns
2.  Android UI Design Patterns
3. Gradient Shape Generator Online

 Android Game Development 

1.  Against the grain – Game Development Explained
2.  AndEngine – Game Development
3.  Rokon – The Open Source 2D Game Engine for Android
4.  LibGDX – Android Game Development Framework
5.  Android-2D-Engine – Engine for 2d games written for android in c++/java
6.  Angle – Android GL Engine
7.  jPCT-AE – Free 3D Engine for Android
8.  LGame – Android and J2SE Game Engine
9.  Alien3D – Android 3D Game Engine
10.  CatCake – Open Source Graphics Engine
11.  Cocos-2D-Android – A framework for building 2D games for Android
12.  CoronaSDK – Cross-platform Mobile Application Development Framework
13.  Unity3D – Framework for Cross-platform Game Development

 Android Embedded, Electronics & Automation 

1.  Android in Industrial Automation

 Android Technical Blog 

1.  Tech Droid – Tips for Android Developers
2.  The Developer’s Info – Android, Java and more…
3.  My Life with Android
4.  About Android
5.  Think Android
6. Android-er

Resource Icons 

1.  IconArchieve
2.  FindIcons
3.  IconFinder
4.  IconLet

That's all the recommended free site to learn Android Application Development. Hope this article useful for you.
Are you favorite sites not in the list? Feel free to mention it in comments below.