Udacity offers great content for Android Programming in their Nanodegree programs. If you don't have the money you can take same of the courses for free (but without certificate). The skills you learn in this Nanodegree program will accelerate your journey to becoming a working Android Developer. this program teaches the tools, principles, and patterns that underlie all Android development.
- Java Programming Basics
- How to Install Android Studio
- Android Basics: User Interface
- Android Basics: User Input
- Android Basics: Multi-screen Apps
- Android Basics: Networking
- Android Basics: Data Storage
- How to create in Android
- Object Oriented Programming in Java
- Developing Android Apps
- Advanced Android App Development
- Gradle for Android and Java
- Android Performance
- Material Design for Android Developers
- Mobile Design and Usability
- UX Design for Mobile Developers
- Add Google Maps to your Android App
- Google Location Services on Android
- Add Google Sign-In to your Android Apps
- Passwordless Login Solutions for Android
- Firebase in a Weekend (Android)
- Firebase Analytics: Android
- Google Analytics for Android
- Monetize Your Android App with Ads
- Android TV and Google Cast Development
- Android Wear Development
- Android Auto Development
- Android Interview Prep
- How to Make a Platformer Using libGDX
- 2D Game Development with libGDX