One of the things I take note of first when I consider an add-on is the last time it was updated. I feel better now that I've looked at the reviews. I'm pretty sure I'm not the only one that does that. Just some food for thought.
While the screen-capping and editing work great, clicking on any of the share buttons ends with a greyed-out screen and the "working" cursor. (see http://imgur.com/l26rHXw - Pinterest is highlighted, but same behavior occurs for other share buttons) I'm running Aurora 22.0a2 (2013-04-11) and Win7. I also tried it in Firefox 20.0 Portable, both "normally" and as administrator -- same behavior. :-(