Great extension. However there are some annoying issues - 1. When you open firefox, it defaults to 'on', meaning if you are using your browser and don't need to block any sites (which is 80% of the time for myself) you will need to turn it off every time you open firefox. 2. This isn't as annoying but still weird - when you visit a site that is blocked, it redirects you to a mozilla addon link, e.g (moz-extension://0176857e-3c38-4d6b-bebc-2a1400810453/resources/redirect.html) rather than retaining the original link while displaying the impulse blocker alert.
