NexusDialog - Allows you to easily and quickly create forms in Android with little code.
Nice option too for creating interesting app logos.
AndroidFillableLoaders - Fillable progress view working with SVG paths.
MaterialProgressBar - Material design ProgressBar with consistent appearance.
DragSortListView - Extension of the Android ListView that enables drag-and-drop reordering (No longer maintained).
#GENYMOTION VS HOCKEYAPP FOR ANDROID#
Crouton - Context sensitive notifications for Android.
Flow - Library that helps with describing an app as a collection of moderately independent screens.
AndroidQuery - Android-Query (AQuery) is a light-weight library for doing asynchronous tasks and manipulating UI elements in Android.
AndroidStaggeredGrid - Grid view which supports multiple columns with rows of varying sizes.
Cardslib - Android Library to build a UI Card.
Pull to refresh - A swipe refresh layout is available in the v4 support library.
Rajawali - Android OpenGL ES 2.0/3.0 Engine.
Unity - Cross-platform game creation system.
Libgdx - Cross-platform game engine and SDK.
AndEngine - Free, Fun and Fast Android 2D OpenGL Game Engine.
AndroidAnnotations - Java annotations with dependency injection at compile time.
ActivityStarter - Android Library that provide simpler way to start the Activities with multiple arguments.
Butter Knife - View "injection" library for Android.
Dagger 2 - A fast dependency injector for Android and Java.
Dagger - Dependency injection framework for Java and Android.
RoboGuice - Dependency injection framework for Android.
Data Binding Library - Official Android Data Binding Library to write declarative layouts and minimize the glue code necessary to bind application logic and layouts.
RoboBinding - A data-binding Presentation Model (MVVM) framework for the Android platform.
Provides data binding and event listener binding, fits well for MVVM.
Anvil - A small library to create reactive UI components, inspired by React.
CloudRail - Unified API Library for: Cloud Storage, Social Profiles, Payment, Email, SMS & POIs.
MPAndroidChart - An Android chart and graph library supporting scaling and dragging by gesture.
HelloCharts - Chart and graph library with support for scaling, scrolling and animations.
WilliamChart - Chart library with good motion capabilities.
For general Java libraries have a look at awesome-java. A curated list of awesome Android libraries and resources.