Android Development Tutorial and Reference

• Official Android Developers Page (Development)
• Official Android Developers News
• Official Android Blog
• Android Tutorial @ Vogella
• Styling Android (Guide for applying styles and themes)
• Android Tutorials @ Mobiletuts+
• The Android Toolbox @ Android Weekly
• Android Bootstrap
• Ongoing Dev – Gabriele Mariotti

Android Design Guideline and Design Resources

• Official Android Design Guideline
• Official Android Design Resources
• Android Asset Studio
• Android 4.0 Ice Cream Sandwich design startkit (PSD)
• Android ICS/JB Photoshop GUI Design Kit
• Android ICS/JB Action Bar Icon Design Photoshop Template
• Android UI/UX Icon Pack #1
• Android Google Play Icon Template
• Android GUI Stencils, Kits and Templates @ Speckyboy
• Android Developer Icons
• Printable A4 Sketching Kit
• Fluid UI (Online Wireframe Tool)
• Proto.io
• Android Cheat Sheet for Graphic Designers
• DPI Calculator

Android Design Patterns, UI, Layout

• Official Android Design Patterns
• Android UI Patterns
• Android Patterns
• Android UI Design Tutorials @ Mobiletuts+
• Android Development Blog by Cyril Mottier
• Designing and Implementing Android UIs for Phones and Tablets (Google I/O 2011)
• Android Design Patterns by Giorgio Venturi
• Android UI Patterns app by Groidify
• The Ultimate Android Library (Google Play App)
• Android Views
• DevAppsDirect

Android Apps Showcase and Collections

• Holo Everywhere
• Holo There
• Android Niceties
• Android App Patterns
• Android Samples
• Android Pttrns
• Mobile Design Patterns Gallery 
• Holo Themed Apps Collection @ The Verge
• Android UX

Android Newsletter

• AndroidDevWeekly
• Android Weekly

Feel free to drop me some link for any awesome resources for Android Designers and Android Developers!