Can't give this any better rating as the add-on is not intuitive at all. I thought that the purpose is to open several tabs, save those tabs into a group and then reopen them again later. Problem is that as soon as you close the individual tabs they disappear from the group. What good is this add-on if the groups don't keep their list of tabs to reopen them later? There needs to be a tutorial that explains how this is supposed to work.