windowed-fullscreen-video troch Cubimon

This plugin works on all websites, that use html5 video directly on the DOM (not in iframe), e.g. Youtube or Twitch. Simply click on the icon in the extension bar, while the video is visible, to display it at maximum size in the current window. To undo the windowed fullscreen view tap the icon again or alternatively reload the page. Source can be found on github.