Examine source code of Spin the Wheel Custom

{
  "manifest_version": 2,
  "name": "Spin the Wheel Custom",
  "version": "1.0",
  "description": "A customizable spin wheel with modern design",
  "browser_action": {
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage"
  ],
  "applications": {
    "gecko": {
      "id": "spinwheel@example.com"
    }
  }
}