Works pretty on all sites I visit where I want to download videos encoded in blob format. It can be a bit tricky learning how it works in the beginning. But once you figured it out, it works nicely. The download step takes you to a special website where the video is streamed and you get a download link.

This doesn't work on YouTube

Looks like spyware

does not work.

doesn't work with youtube

Yes

Does nothing!

well, really strange plugin - on a page with chunked video stream "blob:httрs://..." without any e.g. .m3u8 descriptor it just does nothing, even doesn't show it's active.

the other cases of web media streams are handled by e.g. VLC best way, so i don't need any extra tools at all.