An electronic device may include a finger-operated input device, and a finger sensor carried by the finger-operated input device to sense a user's finger. The electronic device may further include a processor to perform applications and perform at least one device function responsive to an operation of the finger-operated input device. The processor may acquire finger-matching biometric data of the user's finger responsive to each operation of the finger-operated input device. The processor may further authenticate the user based upon an authentication request from one of the applications. The authentication may be based upon a match of most recently acquired finger-matching biometric data and finger-enrollment biometric data.