Idea is great, as I was looking to replace the wonderful DownThemAll which is nolonger compatible with Firefox.
It was working fine for some time, with all the limitation stated by other reviews (opening lots of dialog windows for each file to download, no way to put all files on the same folder for multiple files automatically...)
But since weeks and for the last Firefox version, it does not show any to download on any pages, neither video, pdf, and so on. Sad that it is not working anylonger at all.