Signal is fine for normal/social chatting. It is centralised which makes it much harder to obscure identifying conversation metadata, and I wouldn’t recommend it for comms with a state threat model. I like SimpleX for addressing those issues.
If you just want to chat to friends and nothing else, I probably would recommend Signal for the most polished experience and most widely adopted open-source private messenger.










Haha I used to do this all the time for my credit card PIN. Every time I had to enter it I had to get out a calculator as I didn’t remember the four-digit number but I did remember the expression I used to derive it.