Here are a few more customizations and tips worth mentioning:
- To add/remove the toolbar icon right click on the Firefox toolbar and select “Customize…”
- To change settings go to Addon-manager -> Youtube video and audio downloader -> Options
- To get information about Youtube videos such as all possible formats and their download links, first open a video in Firefox and when the toolbar icon is red, middle click on the toolbar button.
- To extract audio files from FLV video, click on the toolbar button, go to Tools tab and then select Video conversion tool.
- To extract all embed videos of current page, Ctrl + Left click on the toolbar button
This is a great extension to download YouTube videos in various formats (FLV, MP4, 3GP, WebM) and extract the audio files. You can also optionally download video subtitles if available! Want to try it out? You can download it from the Firefox Add-ons website.