I tried File Centipede with Firefox, and it can't download from the browser extension using the download button. I have to use the copy button. It can detect but not download everything. Finally, when I download from Youtube, it gets only the video with no audio; the audio's downloaded separately.
Second, I tried the new version of XDM, and it can't download from the browser extension. I also can't seem to download anything even when I enter the URL in the program.
Third, I tried FireDM, and it takes a long time to download some videos. It stays at 99 percent until the two indicator bars are finished, and for some sites there are lots of small video files created. And there's no browser extension.