How to change brightness in iOS 5 app?

Question

How would I program the ability to change brightness in-app? I know that its possible as I have seen at least three apps that can do it. This would be very useful for my app

Answer 1

As others pointed out you can use

[[UIScreen mainScreen] setBrightness:1.0];

BUT be very careful because you will run into problems (talking from experience here) look at this: IOS5 setBrightness didn't work with applicationWillResignActive and this: Anyone been able to use [[UIScreen mainScreen] setBrightness] on background / exit?

(I wish I had, when I discovered this thread/answer) :-(