Rated 5 out of 5 stars

Please Session Manager!!! come back!!! my life is not the same without you!!!

Actually, I downgraded to Firefox 56 just for this add-on.

If you want this add-on to come back just as I do, then ,please, send a feedback to the firefox team to do something about it. Just press "Alt", then Help>submitFeedback... and write about your love for this add-on and don't forget to add the next link at the end of the message.
https://addons.mozilla.org/en-US/firefox/addon/session-manager/

If we all do this they will take it seriously and they will put it back to operation.
Please help with your Feedback!

This review is for a previous version of the add-on (0.8.1.13).