f.lux is one of those things that I don't know how I ever lived without. All through college I worked evening hours on my computer and it was KILLING my sleep schedule (and I'm one of those people who need sleep). Then, in came f.lux and absolutely changed the game. It was weird to get used to the orange hue at first, but oh my gosh, being able to go to bed after working or writing a paper made it 100% worth it. I haven't looked back once.