Best Android Library open source on GitHub and others, enjoy !!

1. Navigation
2. UI Components
3. ListView & RecyclerView
4. Chart
5. Game
6. Parsing
7. Material Design
8. More
9. Android Tools

1. Navigation

• ParallaxPager : ViewPager with Parallax scrolling effects
• ArcMenu : Alternate radial menu (Like Path App)
• SlidingUpPanel : Sliding Up Panel (Like Google Music App)
• DraggablePanel : Panels that can be dragged (Like YouTube App)

2. UI Components

• CircularProgressBar : Realize a circular ProgressBar in the simplest way possible.
• BetterPickers : BetterPickers for easy input selection
• CircularImageView : Realize a circular ImageView in the simplest way possible
• CircularFillableLoaders : Realize a beautiful circular fillable loaders
• ShowcaseView : Highlight the best bits of your app
• View Animations : Easily apply common animations
• ImageSlider : Animated image transitions
• Forsquare-CollectionPicker : Item Picker which looks like Foursquare Tastes picker
• Iconify : Easily embed icons into your app
• GooglePlusLayout : Custom layout that support playing animation on child view in the main Layout that appears on the main page (Like Google + App)
• TimesSquare : Standalone Android widget for picking a single date from a calendar view
• CircularSeekBar : A circular seek bar for Android
• DateTimePicker : Contains a beautiful DatePicker and TimePicker (Like Google Agenda App)

3. ListView & RecyclerView

• ListViewAnimations : Easy way to animate ListView items (Like Google Keep App)
• QuickReturn : Reveal or hide a header or footer as the list is scrolled in a direction (Like Facebook, Twitter or Google + App)
• QuickReturn : Implementation of the QuickReturn UI developed
• Picasso : A powerful image downloading and caching library

4. Chart

• WilliamChart : Flexible charting library with useful motion capabilities
• HoloGraphLibrary : Newer graphing library
• EazeGraph : Another newer library with potential
• AndroidCharts : Easy to use charts

5. Game

• AndEngine : AndEngine is a free Open Source 2D OpenGL Game Engine for the Android platform
• Unity3D : Very good (available on Android, iOS, Web, Windows, OS X)
• Ogre3D : The best open source 3d engine but it is a large framework
• Irrlicht : Good performance, light framework [Game: Moblox]
• Linderdaum Engine : Open source for Windows and Android
• Cocos2d-x : Open source cross platform
• Box2d : Fast and easy
• Jbox2d : So slow on Java that I made a JNI wrapper with SWIG to use native box2d (AndEngine does the same)
• Chipmunk : Fast but I prefer box2d
• Bullet : Excellent 3D engine

6. Parsing

• Retrofit : Type-safe HTTP client for Android and Java by Square, Inc.
• Gson : Gson is a Java library that can be used to convert Java Objects into their JSON representation
• SimpleXML : Simple is a high performance XML serialization and configuration framework for Java
• Jsonschema2pojo : Generate Plain Old Java Objects from JSON or JSON-Schema

7. Material Design

• MaterialViewPager : Material Design ViewPager easy to use library
• Material-Movies : Setup an android environment to develop an scalable, maintainable and testable projects
• Android-ObservableScrollView : Android library to observe scroll events on scrollable views
• Android-Material-Examples : Sample for Android Material Design

8. More

• ZXing : Barcode or QR scanner
• WebServer : Android Web Server (with NanoHTTPD)
• Mupdf : PDF Reader
• Cropper : Image cropping tool
• EventBus : Simplifies communication between different parts of your application
• ActiveAndroid : ActiveAndroid is an ORM for Android
• ButterKnife : Field and method binding for Android views which uses annotation processing to generate boilerplate code for you

9. Android Tools

• ActionBarStyleGenerator : Allows you to easily create a simple, attractive and seamless custom action bar style for your Android application
• AssetStudio : Icon generators allow you to quickly and easily generate icons from existing source images, clipart, or text
• TinyPNG : Advanced lossy compression for PNG images that preserves full alpha transparency
• LayoutFinder : Layout Finder helps you create the code that ties your Android UI and Java code together
• ButtonMaker : Online tool to generate buttons code for Android Apps
• Gradle, Please : It helps you to get exact maven artifact of the particular library
• Postman : It comes handy when you would want to check your rest APIs
• Material-design-icons : Material design icons are the official icon set from Google
• Video-to-gif : Create un perfect demo Gif with your screencast

####References

• CodePath
• Vogella
• Infinum
• Quora
• TechnoTalkative
• GameDev