One of my most used extensions. I wish it was available for Firefox on Android.

Great!

Absolutely excellent. Has every feature I need and more, and I never use firefox without it.

Clean and powerful.

If you're losing your previous sessions or you want better tab management, then this extension is exactly for you.

Does what it's suppose to, easy to use.
I'm a programmer so it helps me pick up where I left off, I can quickly load up my last session and have quick access to all my references and save different sessions with different references for different projects I'm working on without having to make loads of bookmarks and open them all manually. Perfect.

Just restored 19 Sidebery tabs in perfect organization after an Alt F4 to the wrong windows! EXCELLENT extension for fixing the tab restoration issue with multiple browser windows open!

Have to close the first session I open if computer has been shut down or updated, extension doesn't seem to recognize it as a session. Functions normally afterwards.

To quote user tuna's review a day ago
"Firefox has not been able to start since the June 4 update."
I have the exact same problem and in order to make firefox start normally with the extension enabled, i have to start a private browsing session which opens two windows, one with one tab in private browsing and a second normal one with all the tabs that the extension has saved. Otherwise the apllication is killed almost immediately after starting with the extension enabled.