Simplex
Simplex.chat
This is a simple and secure decentralized messenger that does not use identities. Instead, you create addresses for different channels which you can dispose of. This video explains it well. It supports calls and has a desktop interface as well.
I have setup a server to make the network more resilient and spread the traffic. After you install the app, you can go into settings and add these servers:
SMP Server:
smp://nfm-LwDDqi9KDPzebYMbriFXdbE3cHvcfHeEhS-1230=@5.78.46.41:5223
XFTP Server:
xftp://v6P3u9_CPYcgoA79e6tHinywTuzxb6RR6hrSaHrlhzY=@5.78.46.41:5224