One of the must-have add-ons Bewertet mit 5 von 5 Sternen
This add-on is simply awesome.
You can download videos from YouTube and others video portals in Flash, MP4 or WebM, in Full HD, HD or SD. After you click on the "Download" button, you can even close the video's tab and let it work in background while you finish writing that email. :) Besides, it's really easy to use.
And finally I don't have big stuffs to complain about.