Just began testing it on Android, but a security friend and I have been testing the PC clients in both Linux and windows cross platform and it seems to be working very well back and forth from Germany. The TOX protocol and encryption has been verified as the most secure available as true P2P, end to end encrypted, device to device connection without a central server. Voice, video, file sharing, text messaging, Group option...
We are liking it so far.
https://tox.chat/download.html
BTTT