I discovered that f.lux is on my system. I cannot find it in Add-ons, Extensions, or Plug-ins. I want to change some of its settings (both bed and wake times) so that it is actually useful. If I can't change those settings, I want to get rid of it. Is it an add-on, an extension, or a plug-in? Why can't I find it in any of the active lists? And how do I access it to update its settings or (if necessary), delete it? Thanks!