I signed-up for a Mozilla account just so I could leave my review of appreciation for this valuable add-on. Even the low-tech users for our church use this tool widely and successfully.

This is truly an easy way to save a Youtube video to your computer. This is the free tool our church uses to save worship music videos for off-line and ad-free playing. You do have to donate some amount of your choosing ($10 or more) to get the highest (1080p) available option, but what a bargain for such a useful tool.