Element as matrix client. It has some bugs and glitches but is the current best matrix client and the matrix protocol is the best communication protocol i know.
In the current times Signal is the only viable way on mobile. On PC Matrix is a good alternative for chatrooms with friends.
I use Element on Android to access my Matrix account, keeps everything on one network for me that way.
Why Signal over other alternatives like Telegram?
Signal is mainly used by the people I communicate with. The Founder of Signal is also a known Computer Security expert. The signal protocol itself is also used by WhatsApp, Google Messages and Faccebook Messages.
I just had a look at the telegram privacy policy (https://telegram.org/privacy#8-who-your-personal-data-may-be-shared-with) and compared to signals privacy policy (https://signal.org/legal/) telegrams policy is just not for me.
Signal
Signal for private and Whatsapp for work.
I recently started beta-testing Beeper. I was on the hunt/wait for a nice to use client that would be finally able to get all my messengers into a single window for a very very long time (when all my massaging was through XMPP, ICQ and Skype I used to use Trillian), and it is almost it: Telrgram, WhatsApp, SMS and Discord DMs/chat channels in a single app/window.
Keep in mind I value convinience over privacy, but still am mindful about what I send where. Beeper server is not open source, but their bridges are (and encrypt messages before sending to server), and you are able to self host them, I saw in community chat room that some people do that for Signal, so everything is E2E encrypted on hardware under user control.
