If extension slows down your browser too much just open "LeechBlock Options -> General -> Miscellaneous" and mark "Process only active tabs "

Amazing app - very customisable. One of the reasons I stay with Firefox. Wish there were a version for Edge so I couldn't just access my distraction websites that way!

It's easy to use and stops me from accessing distracting sites

This extension does exactly what it's expected to do, easy to set up and figure out. Super useful, thanks!

Better than StayFocusd, so many features and honestly nothing else comes close!

It's very useful. The design can be simplified

Very nice, simple to use, A MUST-HAVE. Thanks James!

This is an annoyingly effective plugin :). By habit I will open a tab and try to go to any one of my distraction websites and it adds just the necessary cumbersome extra step to dissuade me from going.

Helped me with my YouTube addiction

Worked as described. Wish it had a slightly better UI and perhaps a button to add some commonly blocked websites such as Facebook, Twitter, Instagram, Reddit, etc.

Has saved me tons of time!

This extension by James Anderson is truly a blessing. Helps you keep away from distracting web sites during work hours or while studying, it's conditional approach to when to block the sites and then unblock them and then again block them is very helpful!

It works, I just block all websites and use the "+" wildcard to add whitelists to them.
The interface is not that user friendly as compared to Stayfocusd but one visit to the FAQs page and you should be all set.

Vraiment utile et bien conçu. C'est simple, c'est efficace et ça permet de se rendre compte à quel point aller sur les réseaux sociaux est devenu un réflexe et mange un temps fou de nos journées.
De nature anxieuse, j'avais tendance à faire fuir mon esprit à la moindre contrariété en allant sur facebook ou twitter. L'extension installée (et mon smartphone éteint ou laissé chez moi) les effets ont été immédiats, ma productivité a augmenté en flèche et j'ai pu me libérer beaucoup de temps libre ! Je recommande pour tous ceux qui travaillent sur ordinateur.

This is probably the most powerful blocker.