Apple first banned f . lux from their store , then released their own version as a feature on iPhone . Just to give out information , it was banned because F . lux broke out of the sandbox all apps have to remain within for security reasons , as F . lux had to change system settings to do what they do . Of course jailbreaking allowed F . lux to escape the sandbox legally . Releasing their own version could be chalked up to Apple stealing stuff like they have in the past , or chalked up to it being impossible for an app to be able to do so without Apple allowing an exception to the sandbox rule , which would set a bad presenence . As for Android , I ' m assuming apps also have that same sandbox requirment , but less stringent . There ' s likely an API for the overlay available , but it ' s a half measure where you ' d need root to properly drop the blue tones since that ' s typically handled by the graphics side of things on PC , so I infer it functions similarly on Android .