Won't install.

doesn't work

Doesn't work. You have to right click to download the video, but it saves it as a json file, not as a video file.

It simply does not work. It opens the video in a new tab, full screen but there's no way to save it from there any more than there was on the substack page. All you get to save is a jstor file which, of course, is not the vid, doesn't run any vid.
It is a pain in the butt that just causes you frustration and loss of time.