Works fabulously Rated 5 out of 5 stars

Leech Block has helped me conquer much of the internet procrastination that keeps my productivity way down when I am on my computer.
It has numerous options concerning how, when, and what to block that let you really customize your setup depending on what best suits the degree of your procrastination and dedication to accessing those sites (randomly generated long passwords, inability to access the app when it's blocking things, inability to modify sites being blocked at that moment, etc.). I haven't really found any loopholes to it (not that I've been looking), and you can add timers to your browser to see how much time is remaining on your blocked sites.
I also found it very handy that if you right click on any website, you can automatically add it to a list of blocked sites you have without opening up the whole app menu (of course, you cannot remove it in this way!).
All around, it's wonderful.

This review is for a previous version of the add-on (