Based off of Thomas Finch's GammaThingy.
GoodNight is an app that allows you to directly access the screen's gamma
levels, and modify it using IOMobileFramebuffer. With this you can do any of
the following:
- Change the screen temperature
- Put the brightness lower than iOS would normally allow you to
- Adjust the RGB values of the framebuffer
This application uses dlsym, which loads in the private symbols at runtime,
rather than using headers, so no additional setup is needed once you download
the source.
See here.
I am certain that this app will run on any iOS device running iOS 7 or higher. However, nothing happens when turning on any adjustments if using the iPad Pro. Unfortunately, I do not currently have one, so it has hard to test and find the problem. I will do my best to look into it and find a solution.