Examine source code of Spot the Difference Game

{
  "manifest_version": 2,
  "name": "Spot the Difference Game",
  "version": "1.0",
  "description": "Find differences between cartoon scenes.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_popup": "index.html",
    "default_icon": "icon.png"
  },
  "permissions": [],
  "browser_specific_settings": {
    "gecko": {
      "id": "{9fa71853-7f6b-489c-9bbc-65a266e5f528}"
    }
  }
}