Looking for app to dim screen manually

Hi everyone,

Does anyone know if there is an app that you can dim the screen manually? I set my screen at 100 for brightness at all time, and sometimes I just want to dim my screen a little bit when I'm in a very dark area (hurt my eyes). I know I can set my phone to automatic dim my screen, but that's beside the point.. I just want an app that by pressing an assigned button, it will dim the screen for that instance.

If any developer can make this app, please let me know. I think this app will be very useful. :)

I dont think a app for this exists