[vladvasiliu]

You don't need a crappy app. Just write down the seed someplace and compute the TOTP yourself. It's not rocket science.

https://en.wikipedia.org/wiki/Time-based_one-time_password

edit: here's a cli tool for doing this: https://www.nongnu.org/oath-toolkit/oathtool.1.html

[orangepurple]

KeepassXC and KeepassDroid support TOTP tokens in the same record as your username and password for more convenience too

[circularfoyers]

Furthermore, Flatpaks do exist since, like you've stated, it is easy to implement https://flathub.org/apps/search?q=totp

[friendly_wizard]

This is a pretty good one

https://github.com/arcanericky/totp