I love f.lux, thank you. It's on my Mac and on my iPad. It'd be on my iPhone too if I could jailbreak the thing yet.
Oh and here is a bug that's been niggling at me. If you have your laptop plugged into an external display after the evening light kicks in, then unplug the laptop, it's in screaming bright normal colors on its own screen until you quit and restart f.lux. Same if you plug in the external screen in the evening.