I just leanred about another secure chat app.
https://briarproject.org/how-it-works/
From the manual..
"What is Briar?
"Briar is a messaging app designed for activists, journalists,
and anyone else who needs a safe, easy and robust way to
communicate. Unlike traditional messaging apps, Briar doesn't
rely on a central server - messages are synchronized directly
between the users' devices. If the internet's down, Briar can
sync via Bluetooth or Wi-Fi, keeping the information flowing in
a crisis. If the internet's up, Briar can sync via the Tor
network, protecting users and their relationships from
surveillance.
It cooperated nicely on my Android-capable Blackberry. I seems
to operate much like Session, very discreet, and user-
controlled. But unlike Session's putrid neon green for chat
bubbles, Briar is easier on the eyes!
It has a built-in "blog" that can be used to broadcast a
message to all known "Contacts".
--- OpenXP 5.0.51
* Origin: A turtle that surfs the dark web. [o] A TORtoise (2:221/1.58)