The Add-on allows you to select the tabs you want to save as a bundle into a directory. The selection is performed by clicking on the checkboxes that appear in every tab. To save them you click on the red arrow button that appears on the left of the tabs bar. To access the extension functionality you have to have at least two open tabs.
Once the tabs have been saved a blue star will appear in them to remind the user of their saved status. I have also added two other buttons on the tab bar for usability purposes. The first one calls up the bookmarks side bar, and the second one opens a new tab.
At the moment the current version does not work if tab mix plus is installed. It is a tricky problem since we both modify the same xbl file. I will check if anything can be done as soon as possible.
Comments are welcomed!!