Take a look at https://simplex.chat/  Very impressive open source, secure, no personal identifying info.  Cool tech.  I created a chat bot for personal use for fun on top of it as test case. 

 Thanks friend! That's exactly what I ended up doing 💜. I really like it, it's improved so much recently too. UX is getting to be really nice! 

 I discovered it after getting into Start9OS using my DIY NUC appliance (cheap computer) for self hosting app services.