MenacingMightAuthenticator App
chaercoffeei use aegis, it is open source and does not have internet access. you can export and import your secret codes and it has an automatic local backup. it automatically creates a backup of the vault to external storage when changes are made. to backup my vault i use rclone with encryption to backup it to google drive. i also made a termux shortcut script that makes a copy of my vault to sd card.
DustyI switched to aegis a while ago, it's been one of the best apps I've used for authentication. I was using Authelia for along time before that but my backup stopped working unbeknownst to me. I found out while doing a regular backup/restore test it had borked itself.