This is one of the best site blocking apps for Firefox. I can't resist browsing news sites at work. The sites were leeching my time.
With this app installed, I can work with full focus. Thanks Devs.

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.