It's funny how, even after years, it's such an amazing tiny piece of software... that still almost nobody knows about, outside of mostly just the hacker community.
I mean, it's almost a crime it isn't already a native part of OSX and, especially, iOS.
At every new Windows, OSX, iOS, Android release we get new features (some debatably useful - i.e. notification center in OSX, or integration with the new social network of the day) - but some key stuff that would make human-computer interaction noticeably better is just missing.
A few other things that I can't believe are still not standard in a 2014 OS: better copy and paste (the damn thing has been clunky for 30 years, see Ted Nelson's rant), better window management, better support for interacting across multiple nearby computers (Airdrop is a tiny step in that direction), ...
Every once in a while I'll get a little bored with the orange hue (perhaps I need to tweak my settings a bit) so I'll turn it off, and my god! So vibrant but the physical eye pain is tormenting.
You really don't even realize how bad things are until you've F.lux and tried to go back. Try it out if you aren't already using it!
I'm happy to assume that the reason why flux getting reposted and more importantly why it keeps getting upvoted to the front page is because new people are hearing about this great tool everyday.