I go to far too many pointless websites. This add-on means if I try to visit them, I can't. Simple as that. It does what it says on the tin; blocks websites. One left-click anywhere on the displayed webpage and a click on the option to "Block this website", and it is done. Simples. You can redirect to a specified URL, but I've just left it my home page, which I think is the default setting.

It's not a net nanny type ad-on, more of a "Get your work done" kind of thing. Just what I needed. Thanks Allen.