Tab Shepherd by Colin Knapp

Tab Shepherd organizes visible, unpinned tabs across normal Firefox windows after an explicit preview and confirmation. It creates native Firefox tab groups using deterministic local rules, preserves pinned tabs and existing groups, and provides one-click undo. Optional automatic cleanup closes safe tabs unused for at least seven days only when the popup is opened, while a local recovery dashboard lets you restore cleaned tabs individually or in bulk. All classification and recovery history stay inside Firefox. Tab Shepherd does not inspect page content, transmit browsing data, load remote code, or run a network service.