Описание Chat SDK

Chat SDK is a fully featured open source instant messaging framework for Android. Chat SDK is scalable, flexible and follows the following key principles:
Free. The Chat SDK is free for commercial use
Open Source. The Chat SDK is open source
Full control of the data. You have full and exclusive access to the user's chat data
Quick integration. Chat SDK is fully featured out of the box
Scalable. Supports millons of daily users
Backend agnostic. Chat SDK can be customized to support any backend
Features:
Private and group messages
Public chat rooms
Username / password, Facebook, Twitter, Anonymous and Custom Login
Phone number authentication
Push Notifications
Text, Image, Location, Audio, Video, Sticker and File messages
User Profiles
User Search
Typing Indicator
Read Receipts
Location Based Chat
End-to-end Encryption
Cross Platform
Last Online Indicator
User Blocking
User Contacts