Rated 5 out of 5 stars

Not installed yet.

Will it capture a full web page as an image, doesn't say. I'm looking for something that will save with one click, thanks.

This review is for a previous version of the add-on (1.0). 

Just Capture an image

Capture Fox captures the screen and makes a video with the captured frames. Since there are lots of nice extension that do just capturing and even have editing tools, we focus on video stuff. :)
In the future releases, compression feature will be added to let you have optimized and compressed videos.