DO NOT UPDATE. IF YOU UPDATE IT WILL REMOVE ALL YOUR TABS. I JUST LOST HUNDREDS. Terrible terrible terrible add-on.
I have lost tab after tab after tab on this extension but this time it's really one step too far. I have lost every tab I need to work and this is a mess that will take me valuable time to sort out and resort.
Do Not Get OneTab.
It is one of the most unreliable buggy add-ons out there and if you think it will save your tabs you are wrong.
(Note: No, downgrading doesn't fix it, it didn't fix it for me, I doubt it will fix it for you.)