It used to work perfectly. Not anymore.

doesn't work at all with dailymotion videos. But sure is able to show you a bunch of other ads.

使い物にならない。

Bullshitters - Their website claims the add-on is necessary, but it doesn't return the video, just a bunch of advertisements. This Add-on is basically ad bait.

Not intuitive at all. No useful instructions, no indication how to download to your hard drive. You see a string of unlabeled icons and then get a progress bar that says 100%, but there's nothing telling you what to do next or how to save the file you apparently just loaded... somewhere. A ten-second video, or even 2-3 screenshots, would have fixed this.