Select some text, right-click and choose"Search image" in the menu, a Google Image tab will open with your results.
Capture, Reverse Image Search is a powerful capturing reverse image search tool built on top of TinEye engine.
Play YouTube™ Videos in Flash or HTML5 Player
Reverse image search using various search engines, such as Google, Bing, Yandex, Baidu and TinEye.
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™.
Stops video autoplay and shows the preview thumbnail.
Adds a volume slider to Bandcamp album pages on bandcamp.com.
Open and download links in IDM (Internet Download Manager) easily
Forces 1080p playback for Netflix. Source: https://github.com/vladikoff/netflix-1080p-firefox#with-extension Based on https://github.com/truedread/netflix-1080p Chrome Extension
Vid to Mp3 is fast Firefox Addon for Downloading Youtube Videos and Convert to Mp3/Mp4/AVI/3GP and other audio/video format.
Just One Click to download any video from Youtube. Support new Firefox Quantum 57