For me, having used f.lux and still use it, it doesn't seem to work all that much. What is also strange is, my brightness goes up time and time again, it doesn't change back down. I'm not set to auto-brightness. What is really uncool is when I am walking outside and then I try to use my iPhone and I can't see the screen at all. I have to get inside to use it, or just try to press password and change brightness using CC.