I've been using f.lux for months. Not sure if its affected my sleep cycle but it does reduce glare to eyes. I already keep the brightness at the dimmest (osx), so i can't reduce it further at night.
why is everyone putting a dot after the f ?
It looks like they are following the author's lead. I imagine they are trying to highlight the wordplay in the application's name. Where the light (lux) levels that your monitor gives off changes over time or is "in flux". It also makes SEO easier for a common word like flux.