Excellent tool. Only thing probably missing is a 'temporary unblock' feature where the user can unblock a site for only a couple of minutes after the time limit has been reached. The attempts for temporary unblocking can be specified or be set by default.

Edit: Thanks for the reply. This deserves an additional star.

I install this when I want to be productive.

what is 'Blue Cube', 'Space Hook', 'Sticky Media', 'Quitter'
ok so I got youtube, twitter and facebook, but what's sticky media?

Self control has never been easier.

Edit: 1. I miss the option for syncing timers between Android and PC 2. Exporting config on Android does nothing.
Great addon with so many options for managing your time! And huge plus for supporting new Firefox for Android!

This is the best add on to keep us away from distractions specially for student like me this helps a lot as we can set the timing and day for such distractions and even have daily limit for use of such websites