Been using Tab Mix Plus for years and honestly, I can't imagine browsing without it. It gives you full control over how tabs behave — reopening closed tabs, duplicating, restoring sessions, fine-tuning focus and appearance. The latest version still works great even with newer Firefox releases. If you're tired of vanilla tab handling, this is a must-have. https://tabmixplus.org/ has all the info and download links. The forum is helpful too if you run into conflicts. Solid add-on that just works.