Every Second - Realtime stats per second of Apple and YouTube
Imagus - The extension is intended to complement image features that (I think) is missing from Opera by...
You-Get - Command-line utility to download media contents from the web
Image Max URL - Help find larger or original versions of images, including a customizable image popup feature
YouTubeDLD - World's most efficient YouTube downloader. No spam or ads.
Thumbnail Zoom Plus - The official site of the Thumbnail Zoom Plus add-on for Firefox