I really liked this extension.

During the day, I open several tabs related to some college programming homework, and when it comes in at night, just one click to close those tabs, and the next day another click to restore them.
I also use this extension to control multiple email accounts or even multiple Youtube channels.

This extension is a must-have

mdtouha0116@paypal.com

Justo lo que necesitaba para poder brindar soporte a diferentes cuentas, gracias!

Nice, no other browser has this feature. And it made my life easy.
Thanks Firefox.