simple, good. been using for a while. recently started getting "Download Failed" in Firefox when trying to download videos. It ended up being the DuckDuckGo Privacy Essentials add-on blocking the download. I have to disable DuckDuckGo Privacy essentials for YouTube to use this. Also have Privacy Badger Add-On and that one does NOT have to be disabled to use YouTube Downloader.
This is my favorite tool for downloading YouTube videos. It's reliable & user-friendly. Love how it cleans up the name of the video, by replacing spaces with dashes. I'm old school where file names should not have spaces.