I had to get this extension as a replacement for "Session Manager" as the new Firefox doesn't support that one anymore. It's a 5 star program and I absolutely hate giving anything less than five stars...but the only reason why I have is because for work I have tabs open to local html files I created myself, and every time I restore my tabs with this extension it only opens up web pages from the actual web and never opens up my local html files that I need which makes me have to go and open them up one by one. I could do it myself, but I got this extension to keep from having to take time to do that so I don't mix them up and can start working right away. Also, it doesn't ever open all the tabs when there is more than one window saved, usually meaning I have to open up all the tabs myself in the second window as well. Hopefully it can get updated soon. It's DEFINITELY much faster than Session Manager, but I need it to save and open all the tabs ^_^