The list contains some of the best Android Libraries that you should not miss.

GSON is a Java serialization/deserialization library to convert Java Objects into JSON and back It can be used to convert Java Objects into their JSON representation. It can also be used to convert a JSON string to an equivalent Java object. Gson can work with arbitrary Java objects including pre-existing objects that you do not have source-code of.

• Vogella Gson Tutorials
• Getting Started with Gson
• JSON with GSON
• StackOverflow Posts

Android optimized event bus that simplifies communication between Activities, Fragments, Threads, Services, etc. Less code, better quality.

Based on Subscription pattern like RxJava this Bus makes it super easy to communicate especially in Android Architecture Patterns!

• Getting Started with EventBus
• Communicating Within an App using EventBus
• Make a Weather Application Using EventBus
• EventBus and Observer Pattern
• StackOverflow Posts

An image loading and caching library for Android focused on smooth scrolling

Glide is a fast and efficient open source media management and image loading framework for Android that wraps media decoding, memory and disk caching, and resource pooling into a simple and easy to use interface.

• Getting Started with Glide
• Displaying Images with Glide
• Android Glide Image Library
• StackOverflow Posts

A type-safe HTTP client for Android and Java Retrofit makes it super easy to parse JSON response which is otherwise pretty complicated using the regular HttpClient.

• Getting Started with Retrofit
• Introduction to Retrofit
• Retrofit - Creating an Android Client
• StackOverflow Posts