Well what I liked about signal was the locked access and encrypted database to protect any on-device SMS messages from snooping if I lost my phone or having an interaction with the authorities as you can't be forced to give up a password (as opposed to finger print).
So I looked for a fork of signal and found ***Silence on F-Droid. ** *
It has both those features. Again, I'm not using it to encrypt messages E2E... I'm looking at on device security
Room should be empty