TabSaver 2

TabSaver 2 keeps track of the tabs in your open windows. Save a window as a session and you can close it, then restore it with all its tabs later.

• Drag tabs between sessions, or just between open windows.
• Keeps Firefox containers.
• Put a tab or a whole window to sleep so it stops using CPU.
• Opens in the sidebar too: View → Sidebar → TabSaver.

It's a simpler successor to the original TabSaver: sessions are tracked automatically, so there's no need to save one before closing a window.