Double authentication (PIN/pattern/password + fingerprint)
Create an option allowing the requirement of both the fingerprint and the PIN/pattern/password to unlock the phone.
Who will use the new feature?
People who don't want to be forced to put their finger on the phone, and people who entered the PIN/password/pattern while somebody was watching.
What is the target of the new feature for this user?
Why this user would like to use this feature?