Examine source code of Tutorial Mode for YouTube

{
  "manifest_version": 2,
  "name": "Tutorial Mode for YouTube",
  "version": "1.0.1",
  "description": "Enhances the experience of following coding or tutorial videos by optimizing window switching. Use system shortcuts to seamlessly switch between YouTube and your working application",
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/watch*"
      ],
      "js": [
        "index.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{82027206-6d16-4d8e-9c08-96fc47afa73b}"
    }
  }
}