"Amphora provides a simple way to access Youtube and save currently playing content as audio (M4A) or video (MP4) in the blink of an eye. All processing is done locally - no shady third-party services." There are other similar tools, but this one is adfree, tiny, and seems to be portable too. Cons: no settings of any sort. Homepage: https://www.metasudo.com/amphora/
I can't get this to work. I wish I could because it's "powered the youtube-dl engine" which claims to be able download from 100's of sites.
What doesn't work for you? Have you used the keyboard shortcuts mentioned on the starting screen to perform a download (after opening a video)? Note: Amphora appears to be specifically tailored for YouTube videos.