Author of f.lux here:

After reversing the new APIs in iOS9, it’s really really clear that Apple has added lots of great features to iOS (and the new devices) to adjust screen colors. The new models even have RGB color sensing, so they are an ideal platform to build f.lux on. (I was pretty excited about our next version!)

If this were only about reverse-engineering or using LLVM to compile code I wrote, it would be reasonable to fight it. The remarkable thing about their agreement is that it concerns using information that is not provided under the agreement. This is a reasonable term for app store distribution, but it seems unprecedented and heavy-handed for unsigned binaries.

Ultimately, we pulled the app both to show good faith, and also because we were asking hundreds of thousands of people to use Xcode to make accounts and sign our software. When Apple calls up and says they don't want that to happen, it is not really a thing you can fight. It’s their infrastructure, and they can decide how it is used.

We were feeling pretty good about introducing “building stuff in Xcode” to people who’ve never tried it before.

We have been as polite as we can to Apple in hopes that they will open up the platform to developers like us. The demand for f.lux is certainly incredible.

Have you considered open-sourcing your code with a license you're comfortable with? http://choosealicense.com/

As a developer who suffers from sleep disorders (both sleep apnea as well as general restlessness which is fortunately aided by f.lux!), how do I donate to your project (ideally in bitcoin)?