This is really really really good

Improves my productivity at work.

can block keyword... this is a 100% useful feature

Really really good for productivity. It makes it so easy to stop habitually checking a website.

Does what it says. Solid.

Does what it says it does on the box. I really like the customizeability, and the delay pages are great for giving me those two minutes to think about if I really want to go somewhere.

It does what it's supposed to do and it does it good!

Great addon for saving time.
One small bug: the settings screen doesn't display properly on Firefox for Android in portrait mode. The left hand side of the page is cut off (though works fine in landscape mode)

Useful little plugin that helps keep you on task. It has the awesome feature of being able to set different amounts of time for different groups.