Won't save Rated 1 out of 5 stars
I might as well just copy/paste what someone else wrote below because it's simple and to the point:
"My FF is ver18 and when select area & click save selection prompt Me : Sorry, the image is too large, Firefox can not save it."
That has been my experience as well, so this add-on is useless to me, as a user.
I posted an update. It's waiting to be reviewed by Mozilla. Thanks!