CAVEAT: My review isn't based on how the add-on functions - but rather the responsiveness and helpfulness of the add-on author.

I was frustrated, trying to migrate my groups from the Tab Groups add-on (which doesn't work in FF 57) and completely confused by the instructions. I sent a support email(s/he added helpful information to the About section for the extension, two alternatives for those in my position, and even a third option in the email to me.

With such a positive response to my negative email - I'm certain users of this add-on will find the developer equally responsive to questions and suggestions.