The Apollo Android GraphQL client is a library that generates Java models from standard GraphQL queries, providing a typesafe API to work with GraphQL servers. It includes features such as code generation, network calls and caching, RxJava wrappers, and optional support. The library aims to simplify the process of working with GraphQL in Android applications, allowing developers to create complex queries and manage data efficiently. With its open-source nature and community-driven development, Apollo Android has become a valuable resource for Android developers looking to leverage the power of GraphQL in their apps.