Examine source code of YouTubeTime

{
  "manifest_version": 2,
  "name": "YouTubeTime",
  "version": "1.0.3",
  "description": "Updates the URL with the current time of the video.",
  "icons": {
    "48": "icons/ytt-48.png",
    "96": "icons/ytt-96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/watch*"
      ],
      "js": [
        "index.js"
      ]
    }
  ]
}