Same here, I'm liking it a lot but I'm not sure if it's calming and helping me go to sleep. It's 1:30 am and I'm still in bed, wide awake.
Is there an iOS version 
um, maybe your problem is that you're going to bed with a laptop?
f.lux isn't some magic wand. it's suppose to ease the transition between you staring at your monitor and your bed. if you're actively using your pc to the point its stimulating multiple parts of your brain, then it will make a marginal difference, but if you're conscious of what you're doing, ease down a bit, it will work wonders.
also you have to let f.lux slowly ease its way in since it's very sensitive to the time of day which it's running. during the middle of the day, you won't see a difference between it running or not but you will come dusk. try running it all day and turning it off in the middle of the night, you'll quickly go back. it's just jarring to turn it off for the first time; i quickly turned it off myself the first time i installed it.
though my only complaint is it only lets you disable it for an hour while i'm doing work, watching movies or playing games so i just turn it off completely and sometimes forget to turn it back on.