Examine source code of BackToOne

{
  "manifest_version": 2,
  "name": "BackToOne",
  "version": "0.4resigned1",
  "description": "Disables YouTube autoplay feature and brings focus to the currently playing video.",
  "icons": {
    "48": "icons/backto1-48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "css": [
        "fix.css"
      ],
      "js": [
        "backto1.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c75d06f5-6085-4c11-9615-eba3c1400dd0}"
    }
  }
}