How can I tell if it's working? Rated 1 out of 5 stars

I've installed the add-on, but how do I know if it's doing anything? There should be a way to see what is being blocked. The rather sparse PrivacyWatch website promotes TrackerScan as a way to see the trackers. A link installs an add-on called TrackerWatcher (same thing?) The TrackerWatcher toolbar button opens a completely empty page.

This review is for a previous version of the add-on (