Continuing the discussion from Android fingerprint login:
@Davina_rightgig raises a good question… how long does the app stay logged in when you’ve left the app, before you need to enter a password/Touch ID.
The answer is that it stays for 30 seconds. This allows you to copy details to/from the app or manage tasks without the need to keep entering your password/TouchID/FaceID. It can’t be changed currently.