SimpleX is quite nice, though still not as reliable as Signal.

This post about project direction concerns me a little as it seems confused. What's all this about "XMR while it's legal" stuff? And accepting fiat payments etc? Gift cards are also regulated. 

I suppose you could use Cosmos or Near to build your blockchain and I don't have any strong opinions against that.. but this whole compliance thing just seems plain stupid to me. Are you going to comply with Europe's Chat Control too, and all future versions of it?

Better that you adopt a minimalist blockchain like Grin ツ who's interactive nature seems lille a much better fit for chat.