Every time when alarm wake up, the system will offer you four random numbers. You should remember this number set and then rotate your cell phone to let the arrow point to the numbers in sequence and keep the arrow pointing to each number until the flip-card flips.
version2: add snooze settings and menu key function
Tags: number lock , key lock clock , key lock , keylock , number key lock , pm key lock clock , key lock clock. , number lock screens