I want to manage my time, but I always forget that I have better things to do when I have a moment to sit down and waste time on reddit or comic books. I would

I want to manage my time, but I always forget that I have better things to do when I have a moment to sit down and waste time on reddit or comic books. I wouldn't mind a service providing an interstitial before a blacklist of time-wasting sites with my interactive to-do list on it, perhaps with a lens flare over the more urgent items or something. That isn't this program, but it'd be useful to me.