It works, and has some extra features (every time I try to open YouTube, I get directed to "Shouldn't you be studying?" with David Tennant).

Truly block the unwanted sites. Nice one. A redirect option to custom website may be more helpful. Thanks!

Good idea but this extension needs stronger security. My 11 year old son simply disabled the extension to get to the blocked website (Youtube). Aside from requiring a password to remove a website, the password should also be needed to allow (or disallow) a user from simply disabling the extension. Looking forward to a fixed extension with stronger security features.

Nice and useful. It would be better if you could add an option to automatically close the blocked site (the tab, I mean) instead of showing an option to type in a password. Sometimes we just want to entirely skip those sites.