In the run-up to Apple introducing Night Shift mode in iOS 9.3, automatically adjusting the color temperature of the screen to reduce the amount of blue light as daylight ends, it also required the developer behind third-party app Flux to cease making their app available on iOS devices.

When one German customer emailed Apple’s SVP of software engineering Craig Federighi to suggest that Night Shift had more blue light than Flux, he received a reply explaining that there was good reason for this, reports iFun.de.

If you haven’t yet tried the feature, check out our video walkthrough.

Given the display technology, we push it as far as we can without introducing major red ghosting artifacts when scrolling/animating. (Unfortunately, the red phosphors in the LCD hold their color longer, and when we shift the display too far into the red then scrolling results in irritating ghosting artifacts.