Apple has just about the best legal team of any company out there. Do you seriously believe that they didn't bother looking into the current patent application that f.lux has filed?
The norm for most tech companies (including Apple, I think) is to explicitly avoid looking at those sorts of patents so that you can claim ignorance if it ever comes up in court. So yeah, I doubt they did.
And even if they did get a patent granted and Apple was infringing on it, the payout wouldn't be much. How much is their monetary loss, based on the fact that they don't charge for the product? Apple would make a payout and move on.
By controlling the product, f.lux can potentially turn it off or start charging money for it or start making money through ads or whatever at any point in the future. So the damages need not be related to the cost of the f.lux product. In fact, a damage award would be more likely to be based on the amount of money that f.lux would charge a third party for the use of their patents in somebody else's product, which is entirely unrelated to the cost of the actual product from f.lux.
There is a very simple rule for apps on iOS, whatever you do in one app should never affect anything outside this app. It is a fundamental principle that allowed everybody to install stuff at will without any fear of borking things up, of doing any damage. F.lux clearly breaks that rule.
There are very few calculated exceptions from this rule:
...
There are a boatload of exceptions to that rule, starting with app extensions, which allow third-party keyboards to draw custom user interfaces on top of arbitrary apps and handle keyboard input for those apps....
Compared with that, allowing an app to change the display's color temperature is so far down the "not a legitimate security concern" ladder that it fell off the bottom rung and into the lake.
Besides, you don't have to grant blanket permission to use those SPIs. Just grant permission on a case-by-case basis for developers that have a legitimate reason to use them.
There is nothing slimy about this. Apple doesn't now, and has never on the past, allowed ANY developer to add an OS level feature to iOS.
Of course they have. They've allowed custom VPNs, custom keyboards, apps that manage Wi-Fi captive portals, configuration profiles that add new root certs....
This isn't something exclusive to Apple. It's something EVERY SINGLE COMPANY in every single industry does, no matter the size. Small companies take features from bigger ones and implement it in their products. Google takes things from others. Everyone takes stuff from everyone.
But not everyone steals ideas from their competitors and then threatens legal action to stop those competitors from continuing to distribute the original product from which they stole the ideas.... Just saying.