I've really enjoyed 1Password's integration with my phone's fingerprint unlock functionality, but I have a small concern from a security/privacy standpoint: there are only 2 rare times when I would get prompted for a master password (fingerprint fails 5x in a row or to change a master password). Given the de facto lawfulness of compelling fingerprint unlocks (eg https://arstechnica.com/tech-policy/2017/01/court-rules-against-man-who-was-forced-to-fingerprint-unlock-his-phone/) and the possibility of fingerprint spoofing by bad actors, it seems prudent to not give fingerprint unlock (or any biometric log in option) permanent full access to 1Password.
An easy remedy would be adding an option to "Log out on exit" in addition to "Lock on exit" in the Android app (presumably iOS too, and potentially desktop systems that support biometric options as well). Enabling this option would force a master password to be re-entered if the app is fully closed (as opposed to task switched away) and allow users to fully secure their data if they want to, while still leaving them the option of keeping the app open in the background if they want to maintain fingerprint unlocks during their current session. Naturally the option would apply to Pin Lock as well (since both "locks" work similarly to each other, but are distinct from "logging out") but that angle is less applicable to my above concerns.
For reference, I know at least one other password management app has this as an additional option, although it's one of only a few places where that app bests 1Password.
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