Yesterday we shared that the popular automatic screen brightness adjusting app Flux had found a way to make it from the Mac to iPhones and iPads on iOS 9. This afternoon the developers behind Flux announced that the app will no longer be available on iOS at the request of Apple. In a blog post sharing the development, the developers behind the app said that Apple contacted them to say that the app violated Apple’s Developer Program Agreement. While the app was unofficially supported on iOS 9 as a sideloaded app and not an official App Store app, Flux did use Xcode signing to work properly on iPhones and iPads.

Flux on iPhones and iPads with iOS 9 was originally made possible due to limitations being lifted around Xcode, which is available for anyone to download from the Mac App Store. Flux no longer being available is the first major instance of signing apps with Xcode and sideloading them unofficially without the App Store going sour.

This is likely due to the popularity that the automatic screen brightness utility enjoyed during its short run on iOS. In the blog post, Flux’s developers share that the Flux iOS page was visited 176,000 times in just one day, in part thanks to being featured on this website yesterday. Flux on the desktop, they say, has been downloaded over 15 million times.

f.lux cannot ship an App using the Documented APIs, because the changes we make are not allowed. In the last 5 years, we have had numerous conversations with Apple about our product and what would be required to make it work with iOS.

We respect Apple’s products enormously, and we urge Apple to allow work like ours to continue through Documented APIs.

You can read the full blog post explaining the situation here.