Examine source code of washing machine

{
  "manifest_version": 2,
  "name": "washing machine",
  "description": "This extension simulates a washing machine in your browser!",
  "version": "1.1resigned1",
  "author": "joak",
  "permissions": [
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "icons": {
    "128": "icon128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "script.js",
        "jquery.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "animationwashingmachine.css",
    "start.mp3"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{77b45692-fc62-4c2a-acb8-101f324d04f1}"
    }
  }
}