Super useful, although there's an issue. Saved windows don't always get restored fully, for example today I wanted to restore a 5-tab window by clicking the "+" button and it opened only the first two tabs plus an empty tab (which was not part of the saved window). I tried opening it again by clicking on one of the tab icons of this saved window, and I got 5 tabs, but the last one got changed to an empty tab instead of the saved website. I hope this can get solved soon.

Edit a couple of days later: Again, I can open max 2 + an empty tab when trying to restore a 12-tab saved window :( Please, fix this asap if you can.