Add-on works without issues. The user experience, however, is not exciting at all.
Session management bar should definitively be on the right site, so you can access tabs by moving the mouse just down, not across a half screen.
Design is disruptive compared to the beautiful Firefox.
And this shouting icon that only means that sessions are not synced (which is every time you change a tab) is absolutely frightful. It is better not to even enable sync.
Highly recommend to hire a UX designer...

同期機能搭載で更に便利になった

Great addon, has been updated to issue features/fixes addressed to be lacking in the previous reviews.
Seemingly the most modern and useful session manager.

This is a great add-on that is very useful. It would be even better if it were compatible with Tree Style Tab, and restored not only the tabs themselves but their tree structure!

I would like to give five stars to this add-on as it's the best session manager but the interface is awfully becoming worse and worse:

- You no longer can select tabs nor windows to be opened. It looks like you can only remove tabs from the tree before opening a session, in which case you destroy the structure. Sessions lose the original structure and you cannot use them in the future as they were

- The maximum width of the side pane is 800 pixels, what does not leave room to access any of the valuable tools and options, such as rename a session, access the menu, see full tab description, add tags, open/delete a session

- You are somehow forced to configure the add-on to open the panel on a new tab which is inconvenient

Excellent functionality and interface.
I have been using the extension for more than two months (~500 hours, PC worker) and so far have not a single failure.
+ there are backup copies of sessions - TabSessionManager - Backup.

The best FF session manager at the moment.
My wishlist:
- Could be a little faster at startup
- FF sync support would be great.
- Possibility to rename saved sessions

very important productive extension. Thanks for save my tabs.

Its a life saver and with cloud sink, its also has life backups.