I use Video Downloader because there are several videos available on You Tube that are not available elsewhere. Many are music videos that I want to play on my devices off-line, without needing to be connected to You Tube. For example, if I am on vacation in a remote location. This extension allows me to save a high quality video or audio file for later use. The quality is WAY better than the readily available MP3 files. I was at first skeptical but am now convinced it is worth the requested donation for the upgraded version. I had a technical support question and the developer responded within 24 hours. That is really impressive when most developers require several days.