*Updated for version 1.10 on 2017-11-29:

THis project is under active development, which is always reassuring. Since my previous reviews, the author has added helpful new user tool-tips and added some polish.

Like some, I have been looking for a WebExtensions successor for OneTab. This application handles the basic premise of "Click to save all tabs from a window, and later restore them to a window". This extension calls its grouping of tabs "sessions" and it uses a provided Firefox sidebar to show you your saved tab groups as collapsible lists.

Overall it handles this basic functionality really well and cleanly; it is much better than the others I have tried. The provided Tab Sidebar is a new part of the project that the author is building on, but I cannot speak to what plans there are to expand the functionality in the future. For those wanting a detailed explanation about the current functionality, I will expand below, but the short of it is: the extension's provided sidebar (Tab Sidebar) allows restores of entire sessions, as well as renaming the sessions, but currently you won't be able to further organize the sessions or the sessions' tabs within this sidebar - you can however do this from the Bookmark Sidebar, now noted in the tool tips. Within the Bookmark Sidebar you can also handle organization of the sessions and sort/move/delete individual tabs.

I will mention that I still think this add-on could be used to build out a complete, featureful tab manager that rivals/surpasses what OneTab originally did. The main potential bonus I can see is it's integration into Firefox bookmarks and Sync. Because it ties into the bookmark system, this should allow a user to sync the sessions through their browsers. Note, I personally haven't tested this, but it should be possible. Potentially even on mobile too!

I think this add-on is worthy of a 5/5 rating on its own, where the main intent was for a simple/clean implementation. As the developer commented to me, it was orginally intended as a simple implementation, and it does this really well!

For more details about my description, what this extension appears to do is create a bookmark folder, and when you save a new session, it adds the session tabs within a new sub-folder. I think this approach is rather clever, with some real potential benefits, a-la Firefox Sync, where this folder structure and session-folder bookmarks could be shared between browsers. In general though, from the bookmarks sidebar (or bookmarks manager window) you are able to reorganize the the folder order (the session folders are shown in reverse order to how they are listed in the Tabs Aside folder), and you are able reorganize bookmarks/tabs within (and between) these folders. In fact, I could see some power users preferring to use this add-on as a method of quickly creating sessions, and then using their own bookmark manager for organization (ie the bookmark sidebar).

Currently, the extension's Tab Sidebar is tied into the behavior of the session creation. When you save a session, it opens the Tab Sidebar, makes the new session list, closes the tabs, and opens a new tab page. A couple of configuration options here could really help allow users to make this part of the experience as personally efficient as possible.

For future feature requests, I think being able to further handle organization from within this Tab Sidebar would be really slick, ie changing their order, and being able to sort/move/restore individual tabs (like OneTab did). You could even start building in some of the extra features like "staring"/pinning sessions that OneTab had, while still utilizing Firefox's underlying bookmark system to allow these things to sync across machines.

Just wanted to tell the developer, great job here. I wanted to take the time for this long review and to personally contribute financially because of the hard work done, and hope others will contribute as well. I think this has the potential to be the best Bookmark/Tab Session manager we've seen to date, and can't wait to see what you plan to do with it!

Past reviews:

1.7 Review
https://pastebin.com/wqJebekP