Examine source code of PixelCat

{
  "manifest_version": 2,
  "name": "PixelCat",
  "version": "2.5.7",
  "description": "Adds a playful pixel pet companion to YouTube and Google with animations, coins, fish, spiders, quests, achievements, and unlockable extras.",
  "permissions": [
    "storage",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "src/background.js"
    ],
    "persistent": false
  },
  "icons": {
    "48": "assets/icons/icon48.png",
    "96": "assets/icons/icon96.png"
  },
  "browser_action": {
    "default_popup": "ui/popup.html",
    "default_icon": {
      "16": "assets/icons/icon16.png",
      "32": "assets/icons/icon32.png",
      "48": "assets/icons/icon48.png",
      "96": "assets/icons/icon96.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube.com/*",
        "*://youtube.com/*",
        "*://www.google.com/*",
        "*://google.com/*",
        "*://www.google.co.ma/*",
        "*://google.co.ma/*"
      ],
      "css": [
        "ui/styles.css"
      ],
      "js": [
        "src/quests.js",
        "src/fairplay.js",
        "src/cat-storage.js",
        "src/cat-coins.js",
        "src/cat-fish.js",
        "src/cat-balls.js",
        "src/cat-portals.js",
        "src/cat-speech.js",
        "src/content.js"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    "assets/icons/*.png",
    "assets/animations/*.png",
    "assets/fishes/*.png",
    "assets/balls/*.png"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "pixel-cat@example.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}