Still a lot to do Rated 2 out of 5 stars
This extension is very nice in theory, but in practice it still has a long road to go before it becomes stable.
Firstly, it will lose your account settings every now and then (not only when restarting Firefox).
Second: as soon as it is activated, it has both tab and bookmark sync enabled, so that it will badly mess with your bookmarks.
Third: if you want to disable bookmark sync you have to do it from BOTH your devices (mobile and pc) otherwise it won't stick.
Fourth: even if you correctly disable bookmark sync, sometimes it comes back again.
I sent a couple of bug reports to the developers, but nothing happened so far :-(
Thank you for your Feedback
Dear user, thank you so much your feedback, we'll fix the bugs you mentioned and continually improve our add-on, thank you for your support!