Elon messaged "Signal", as in the app...will be checking it out. He's pretty smart - about some things.
Signal is a cross-platform encrypted messaging service developed by the Signal Foundation and Signal Messenger. It uses the Internet to send one-to-one and group messages, which can include files, voice notes, images and videos.[16] It can also be used to make one-to-one and group voice and video calls,[17][18] and the Android version can optionally function as an SMS app.[19]
Signal uses standard cellular telephone numbers as identifiers and secures all communications to other Signal users with end-to-end encryption. The apps include mechanisms by which users can independently verify the identity of their contacts and the integrity of the data channel.[19][20]
Signal’s software is free and open-source. Its clients are published under the GPLv3 license,[12][13][14] while the server code is published under the AGPLv3 license.[15] The Android app also includes third-party components which are closed-source.[21][self-published source] The non-profit Signal Foundation was launched in February 2018 with initial funding of $50 million from Brian Acton.[22] Signal has more than 10 million downloads on Android.[23]
https://en.wikipedia.org/wiki/Signal_%28software%29
Careful with Signal. Dorsey just instructed Jan 6 persons to use it. Why?
https://loomered.com/2020/06/10/jack-dorsey-instructs-users-to-move-riot-related-communications-to-signal-app
Research Signal for us and let us know what you find. Lots of us are mixed on it. Some say Twitter can monitor Signal users. There is some background to it as a former Twitter exec helped found Signal. But I don’t know.
Telegram App may be better. Some criticize Telegram as its CEO is/was Russian. I checked him out a bit and he seems Ok. Some of the strongest anti-communists are Russians.
I’ve had good success with it fwiw.