Wickr - Wickr is a free end-to-end encrypted text, video, picture and voice messenger with full sender...
Yac - Take your time back from Zoom & Slack
Confide - On the off chance that you need to get your messages private and encoded then utilize Confide that will fill in as your own and classified courier.
LinkedIn Voice Messaging - Communicate when you want, how you want
Bleep - Bleep is an insured and secure messaging application by the Bit Torrent that you can use for valuing the private and safe communications.
Slack - A messaging app for teams who see through the Earth!