The addon is not bad, at first glance. He copes with the assigned tasks, BUT very frequent begging for money (donations) is very annoying. I even started writing down the dates when the internal "thank the author" timer went off.
07 06 2026, 15 06 2026, 29 06 2026, 02 07 2026
And I was just opening a window to clear saved sessions.

Soliciting money all the time. Clunky. Sync tends to clutter everything because default settings haven't been thought through well enough. Does work pretty well, but if you're going to bug me for donations all the time, I'll just uninstall.

One of the best extensions I've installed. Simple, effective, and doesn't bloat the browser at all.

Thank you, wery much. for work. for life.

Better than Firefox's built-in backup, but unnecessarily complicated!
I don't see the point of many of the features. Unfortunately, there's no help section to clarify this.

From the volume of open issues and the lack of activity on Git, It looks like Sienori has either abandoned this extension or doesn't have the time to maintain it. April 26.

Auto-save doesn't work, hence data loss

For years, this add-on has suffered from a persistent bug: after an unknown background action, the "Open" button in the Saved Sessions Manager suddenly stops working. I’ve spent several hours troubleshooting, but the technical root cause remains elusive.

Here is what I have established so far:

Profile Corruption: Something is corrupting the user profile. Creating a fresh profile resolves the issue, but only temporarily.

No Add-on Conflicts: I have 100% ruled out conflicts with other extensions.

Clean Install: The issue is not caused by leftover data; a full, clean re-installation of Firefox did not fix it.

The most important point: While I cannot pinpoint the exact trigger in the code, I am able to reproduce the bug reliably. I am happy to assist with further questions or testing.

I normally really like and enjoy this add-on, but there is a horrible bug, which from time to time deletes all sessions and lefts a blank session manager. I dont know if it has to do with updates or something like that. But just today after a long time not saving my sessions in a separate file they are gone.

saved my 3k tabs session