Works wonderfully. Yes, sometimes the download doesn't come through the first time -- but that's on the Youtube end, and this developer works like crazy to find fixes. And yes, when there's an update a new tab will automatically open in Firefox explaining the update and asking for support. Reviewers who say there's no way to stop this are just dumb: to stop it, uninstall the extension. Duh. I think it's reasonable for developers to ask for a little support. I personally haven't found a better YT downloader. And my computer has not been invaded by scammers.