Rated 5 out of 5 stars

This add-on has saved my butt more times than I can count. About half of the time Firefox crashes, it cannot restore the tabs last open on its own. And since I usually have at least 20 tabs open, of articles/etc. that I DON'T want to lose, it has always been quite the experience whenever it happened.
But with session manager, I believe it only happened once that it was unable to "recover the last session" (as it will ask you upon starting after a crash). And even then, I was able to load the session saved shortly before the crash.
All browsers should have something like that! (Or at least have tabs crash protection that ALWAYS works)

This review is for a previous version of the add-on (0.8.0.8.1-signed).