Great Add On, but... Rated 4 out of 5 stars
The product itself is great, but there are a couple of suggestions I would like to make, if I may:
First, there needs to be a way to make the enable/disable feature password protected. As long as it's so easy to turn off, it renders a great product nearly useless.
Second, it would be really cool if it kept a log of all the sites that were blocked. Any program like this is get-around-able. But if someone is trying the hit-or-miss method to get around the software to find something inappropriate, they are liable to run into a lot of blocked pages along the way. But if they know that every blocked page they go to is logged for someone else to look at later, that might help prevent the attempts.
Just a couple of thoughts.