Locks a bookmark to current tab so that you can pick it up where it left off
Click the extension icon to move your bookmark to the current page. If it does not already exist, it creates a bookmark under Other bookmarks->Moving bookmarks. If a bookmark is found, the badge changes to 'L'. This indicates that the current page is bookmarked. If you click the icon, the badge will change to 'M'. This indicates that the bookmark will be moved when you browse to a new page.