math.lock

With math.lock, users can sharpen their mental math skills without ever needing to access the home screen! Math.lock allows users to unlock their phones by solving randomly generated math problems that are displayed every time the phone screen is turned back on. Math.lock also works well alongside other standard lock screens and lock screen applications.

For Android 6.0+

Additional features include:

-simple access to lock screen

-division, addition, multiplication, and subtraction problems

-negative numbers

-functioning lock screen display even after the phone is restarted