I tried SimpleX but the VPN kill switch on my phone prevents syncing with my computer.
I use telegram primarily as a note taking app with sync features.
Occasionally I send files to friends, so having easy set up for tech illiterate would be great.
Well signal also has the note to self.
People will hate this, but WhatsApp is probably the second best and convenient to most people. (But if your friends are willing to get signal, do it.) In fact it was always better than telegram, there I said it.
Also there’s many great note taking apps that have a sync feature. Joplin for one.