This app is for changing the screen bright to max or min. If it was at maximum level it will change to minimum and then it will finish.
This is it, no more options.

It is a very simple application, but very useful when you are under the sun and you cannot see the screen, as you have the bright to minimum value to save battery.

I have it in the left hand side upper corner so I do not need to see where it is to activate it.