YouTube™ Repeat Button
This extension adds the missing repeat button to the HTML5 YouTube player. The button is disabled by default. If you need to repeat a single track, simply click on the button once. When the extension is active the button color is white. When the video is finished playing the current track the extension stops the player for one second and start playing the same track afterward.
Note that this extension only works on the normal playing mode. If a track is in a playlist mode and the button is pressed, the extension offers you to switch to the normal playing mode.
This extension is disabled when a new player is opened. If you need the button enabled, use "&repeat=true" to the URL of the YouTube page.