So, next time, when you start SafeInCloud, it validates your authority by scanning a fingerprint and decrypts your data with a password read from Android Keystore.
Note: Android Keystore can be reset (erased) by the system if some system security settings are changed (e.g. PIN changed or a fingerprint re-registered). In this case SafeInCloud will ask you to reenter your password again instead of swiping a fingerprint. Always remember your password!