This is a compilation of resources related to Android App Development.
In this post, I have only shared libraries that are used on a daily basis and are essential for every new Android developer. At the bottom of the post I have also given links to libraries that are not mentioned here. Enjoy :)
Android Weekly - a free newsletter that helps you remain on the cutting-edge with your Android Development.
Ignition - Helps you get your Android applications off the ground quickly by offering ready-to-use components and utility classes
GreenDroid - Makes UI development easier and consistent throughout 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, a REST Client and more
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
Android Patterns - 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 starter kits with 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 color scheme
ICS Apps - IceCream sandwich app screenshots
RoboGuice - Smoothes out some of the wrinkles in your Android development and slims down your application code
Android Annotations - Takes care of the plumbing and lets you concentrate on what's really important. By simplifying your code, it facilitates its maintenance.
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
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 - Provides a reusable pull-to-refresh widget for Android.
Android Validator - Form validator library
Progress Wheel - A custom component for Android that replaces the progress bar
Scroll Bar Panel - Attaches a view to a scroll indicator
View Page Indicator - Provides widgets compatible with the
ViewPager from 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 a color picker in preferences
Segmented Radio Button - Implementation of iOS's segmented control
PhotoView - Implementation of ImageView, which supports zooming by various touch gestures
Smart Image View - ImageView replacement that allows image loading from URLs or the contact address book with caching.
Android Lock Pattern - Users can define their own lock pattern ‒ which is a combination of 4+ dots
Android Mock - A framework for mocking interfaces and classes on the Dalvik VM
Robotium - A test automation framework that has full support for native and hybrid applications
Application Crash Report - ACRA - A library enabling Android Applications to automatically post their crash reports in a GoogleDoc form
Android Studio - A new Android development environment based on IntelliJ IDEA