Examine source code of CleanTube

{
  "manifest_version": 2,
  "name": "CleanTube",
  "version": "1.5.2",
  "author": "n-deleforge",
  "homepage_url": "https://github.com/n-deleforge/clean-tube",
  "description": "Make your Youtube interface cleaner.",
  "icons": {
    "128": "icons/icon-128.png",
    "256": "icons/icon-256.png"
  },
  "content_scripts": [
    {
      "run_at": "document_idle",
      "matches": [
        "https://www.youtube.com/*"
      ],
      "js": [
        "cleantube.js"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4684631f-88c1-45e2-bdd6-324c2ddb9176}"
    }
  }
}