Stream Chat for React Native has multiple examples in the repo. In addition we have "cloned" some popular UIs to help demonstrate the flexibility of the SDK.
Stream Chat for React Native uses the Stream Chat JS client under the hood for most interactions with the backend. The client documentation covers a wide range of interactions that can be performed, not all of these are used within the Stream Chat for React Native SDK but can be integrated within your own app as required.
To help you get acquainted with the Stream Chat JS client we have an easy to follow tutorial on our website. This is a great primer for using the client directly and can also help you understand how the Stream Chat for React Native SDK if functioning under the hood.