Rated 5 out of 5 stars

This is just awesome!

Some minor problems with sites like Google Reader... that have their own keyboard shortcuts (J, V etc.). It interferes. Best would be to have an option to disable the addon on certain selected sites.

This review is for a previous version of the add-on (0.1.7.1-signed). 

Have found a way to synchronize with sites having keyboard shortcuts.
As before, no user setting. =) The new version will be uploaded within the next few days.