This is easily in my top 5 WebExtensions and one I cannot function without but be warned!! Back up your OneTab by importing them at least daily as it is is very flaky and you can easily lose your 500 tabs as I have done on more than a few ocassions. DO NOT USE CCCleaner to clean your hard drive as it will also wipe out all your tabs. I have written to the developers on 3 instances to try to overcome these issues but you will never get a reply which is why I wont rate it with a 5 which it could so easily be. It is the best Tab saver type extension available except for the flaky nature and no support.