Monal - XMPP

There has never been a better time to get into XMPP, a free public chat network no one controls or owns. Monal is a fast and user friendly way to use XMPP. Just download the app,  login or register and you are ready to chat in minutes. It looks and works the way other apps do, so there is no need to “learn XMPP” or even care what it is.

Notable features:
-Open Source
- No Ads! Strong focus on privacy. Does not phone home and does not have "metrics" software 
-  Does not read any personal information. 
- With a direct connection to your server, your password  and all other info is never sent to a third party.
- OMEMO encrypted chat
- Will work with corporate XMPP servers that require VPN
- MUC multi user chat

Implements XMPP certain extensions intended to improve mobile communication.
-  XEP-0357: Push Notifications
- XEP-0280: Message Carbons keep messages in synch between clients.
- XEP-0198: Stream Management to quickly reconnect.
- XEP-0199: XMPP Ping to maintain connections.
- XEP-0313: Message Archive Management to download chat history.
- XEP-0352: Client State Indication for dramatic reduction on power use.
- XEP-0363: HTTP File Upload to send images in conversations.