Architecture:Ignition – helps you getting your Android applications off the ground quickly, by offering ready-to-use components and utility classes.
GreenDroid – It is intended to make UI developments easier and consistent through your applications.
Spring For Android – an extension of the Spring Framework that aims to simplify the development of native Android applications.
DroidParts – a framework that includes DI, ORM, Logging, Rest Client and more.
ORM:OrmLite – provides some lightweight functionality for persisting Java objects to SQL databases
Active Record for Android - lightweight persistence library for Android.
GreenDao – open source project to help Android developers working with data stored in SQLite.
JEPLDroid (port of JEPLayer to Android)
Design:Android Patterns – a set of interaction patterns that can help you design Android apps.
Google Android Design Guide – official android design guide by google.
Android App Patterns – 1225 app screenshots in 29 categories all in one.
Android 4.0 Design Startkit – some startkit Photoshop PSD’s.
Android Niceties – a collection of screenshots encompassing some of the most beautiful looking Android apps.
Android Holo Colors Generator – allows you to easily create Android components with your own colors for your Android application.
ICS Apps – icecream sandwich app screenshots.
Dependency Injection:RoboGuice – smoothes out some of the wrinkles in your Android development and slims down your application code.
Android Annotations – it takes care of the plumbing, and lets you concentrate on what’s really important. By simplifying your code, it facilitates its maintenance.
Networking:Loopj – an asynchronous callback-based Http client for Android.
Volley – it manages the processing and caching of network requests and it saves developers valuable time from writing the same network call/cache code again and again.
UI:ActionBarSherlock – designed to facilitate the use of the action bar design pattern across all versions of Android with a single API.
NineOldAndroids – library for using the Honeycomb (Android 3.0) animation API on all versions of the platform back to 1.0.
Pull To Refresh – this project aims to provide a reusable Pull to Refresh widget for Android.
Android Validator – form validator library.
Progress Wheel – a custom component for Android intended for use instead of a progress bar.
Scroll Bar Panel – allows to attach a View to a scroll indicator.
View Page Indicator – widgets compatible with the
ViewPagerfrom the Android Support Library and ActionBarSherlock.
View Badger – a simple way to “badge” any given Android view at runtime.
Universal Image Loader – powerful and flexible instrument for asynchronous loading, caching and displaying images.
ColorPicker – to create color picker in preferences.
Segmented Radio Button – implementation of iPhone’s segmented control.
PhotoView – implementation of ImageView that supports zooming, by various touch gestures.
Smart Image View – ImageView replacement which allows image loading from URLs or contact address book, with caching.
Android Lock Pattern – users can define their own lock pattern ‒ which is a combination of 4+ dots.
Testing:Android Mock – a framework for mocking interfaces and classes on the Dalvik VM.
Robotium – test automation framework that has full support for native and hybrid applications.
Tools:Application Crash Report – ACRA – a library enabling Android Application to automatically post their crash reports to a GoogleDoc form.
Android Studio – a new Android development environment based on IntelliJ IDEA.
Some more helpful:App Dev Wiki
Open Intents Android Libraries
Vogella Useful Android Libs
This List will be updated soon Stay tuned.
Very Nice List
RoboGuice Tutorials. Can you provide me the tutorials about Mockitos and Robolectric please?