I have setup XMPP Prosody a communication-chat server on my raspberry pi 3.
It works great! I have installed chat clients Adium on Mac and Astrachat on iPhone and Android phone. AstraChat client is great it lets me share files and make voice call but is limited to Astrachat only, and it's also not available for debian and mac platform.
Is there chat server-clients applications which are cross platform and can share files across multiple devices without any much of a hassle?