Changes screen gamma on iOS, no jailbreak required
RIP official sideload f.lux (https://justgetflux.com/sideload/)
With the new Night Shift feature on iOS 9.3, this is pretty much obsolete. Unfortunately 32-bit devices can't use Night Shift, so this project might still be useful to some.
This project is in no way associated with f.lux.
I talked with Britta Gustafson about this idea/project at jailbreakcon 2015, and she felt that I should contact the developers of f.lux before publicly releasing anything to do with changing the screen temperature. I know they don't have a monopoly on it, but they care very deeply about what they work on and have poured their lives into a piece of software which they feels improves the lives of others (which it does). Aside from that, f.lux has a home on practically every jailbroken phone, and I wouldn't want to hurt the feelings of anyone so important to the jailbreaking community by making a cheap knockoff of their work just for fun. Besides all that, this is not nearly as complex or well-designed as the actual f.lux application and most likely will never come close. The developers of f.lux have spent a lot of time perfecting what they do.
I don't know which license matches this so I'm going to write it out. You can do what you want with the code, but do not distribute compiled copies of the app, especially on mass download sites.
This can't be compiled for or run in the simulator so don't try it, it won't work.
If you find the display glitching while GammaThingy is enabled, ensure that you have disabled
Reduce White Point in iOS
Settings / General / Accessibility / Increase Contrast
URL Scheme Support
GammaThingy supports URL schemes to switch the orangeness.
For the base URL
gammathingy://orangeness/switch those (optional) parameters are available:
enableto toggle orangeness on / off (for values
0), if not provided, the orangeness is just switched
x-sourceto supply a protocol to open after switching orangeness (e.g. to switch back to another app)
closeto make the app quit after the action was executed if its value is
gammathingy://orangeness/switch?enable=1&x-source=prefs enables orangeness and then attempts to open the Preferences.app
gammathingy://orangeness/switch?close=1 switches orangeness and closes the app afterwards