hedayat, you have never tried Conversations on Android, right?
Open Source, full featured, active development and a lot of features.

Service providers? Just choose one:
https://xmpp.net/directory.php
https://www.jabberes.org/servers/

Own server? No problem:
https://prosody.im/
https://www.ejabberd.im/

What do you want more?
I use XMPP since 2001. All my contacts now use it to.