Rated 1 out of 5 stars
Oh finally figured out you have to right click BUT IT DOES NOTHING. You wasted 20 minutes of my time. BAH!
You LEFT click the icon in the add-on bar and it will scan the current page. Or you can RIGHT click the page and select "Spider this page", which will open the spider dialog and prefill its URL, then you press "Start" to begin spidering.
I will be publishing some proper documentation soon, but in the meantime, I hope that will get you started