youtube-repeat-track
A browser userscript that adds a "Repeat Track" button to the YouTube player
Installation
This script is installed as a regular browser userscript, which requires a browser extension to run it: Greasemonkey on Firefox, or Tampermonkey on Chrome.
With Greasemonkey/Tampermonkey installed, click on the youtube-repeat-track userscript source link to add it to the browser.