Software running in the background is something Apple tightly controls in iOS (battery life and security being major concerns). They also don't let apps make changes to the OS appearance. That may be the wrong approach, but Apple is at least consistent in it. This was either an OS level feature or a no go from Apple's perspective. As a user I'm happy it's a feature!
It's just access control at the framework level. Apple could embed a copy in each application using the framework, but that's inefficient, so they install it at the system level.
However, it has nothing to do with rejecting apps because of it, and offering their own version of the functionality. Apple has always reserved this domain for themselves from day one, and f.lux would have had the exact same problems even if Apple hadn't been doing their own version of it.
Not that I care about Flux. But this is definitely not helping them.
> f.lux is patent pending. Do you make a cell phone, display, lighting system, or other cool sleep tech, and want to talk about collaboration? Email us: support@justgetflux.com
Annoying, but possibly not f.lux's fault.
So happy it is being cloned but it would've be nice if it was just on the AppStore to begin with.
You can compile and sideload any software yourself using XCode and an AppleID. I run Gamma Thingy (a f.lux alternative) on my non-jailbroken iPhone. You can compile and run emulators, use any private API, whatever. Those apps will just never be in the App Store.
I don't want my screen to dim at 15:00/3PM, that's just super annoying instead of useful. Let me input a time for dimming instead.