YouTube High Definition is a powerful tool that will let you automatically play all YouTube videos in HD (High Definition), turn off annotations, change video player size, auto stop videos, auto mute videos, control embedded videos and much more.
Play YouTube™ Videos in Flash or HTML5 Player
YouTube Control Center is an open-source project that aims to enhance the overall YouTube experience by providing the end user with more control in what the playback process is concerned.
Watch YouTube in the full-HD quality or the highest available one
瞬间过滤B站(bilibili.com)刷屏的相似弹幕，还你清爽的弹幕视频体验。 *a tweak for a Chinese website. Please ignore this add-on if you are not a user of bilibili.com.*
Tons of features to improve your user experience on YouTube™.
Discover great sites and earn money: This Add-on simply sets Wisedock as your browser home page. With Wisedock you discover interesting websites, support social projects and earn some money. Use this Add-on if you are located in Europe.
Adds a volume slider to Bandcamp album pages on bandcamp.com.
Vid to Mp3 is fast Firefox Addon for Downloading Youtube Videos and Convert to Mp3/Mp4/AVI/3GP and other audio/video format.
Steam helper browser extension: ability to fetch float values right on trade offer and user`s inventory pages; opskins, csgofast, dapubg, lootfarm inventory prices; trade offers quick view, and much more!
Enhances the Steam experience!
This tool will change the session on crunchyroll.com to an american one when the site is visited from somewhere else.