Great addon. Very usefull. I backup the list of urls now and then to be safe, but it works fine for me.

It could use more user friendliness like shortcuts for more actions or more options to arrange the urls in the list and behavious of the groups.

Please cooperate with these guys, gestures would be very usefull.
https://github.com/marklieberman/foxygestures/issues/146
https://github.com/Robbendebiene/Gesturefy/issues/135