The installation is very straight forward (it’s exactly the same as installing any other Firefox plugin). After Firefox has been restarted, you’ll notice a small iWebTool button in your Status bar.
Selecting this button will bring up the iWebTool menu –
Unfortunately, this plugin seems to suffer from some visibility issues if you’re using Firefox in OS X, as seen in the screenshot below.
If you select Domain Check-ups and then Domain Look-up, you’ll be taken to a page that displays a wealth of useful info on the domain of the web page you were viewing at the time.
One other useful feature is the Backlink Checker, which can be found in the Search Engines menu. It will display all of the pages/sites that link to whatever domain you’re currently viewing in Firefox, and the page rank of each of the linking sites.