Examine source code of Steam Price Comparator

{
  "manifest_version": 2,
  "name": "Steam Price Comparator",
  "version": "1.0",
  "description": "Compare Steam game prices between regions from a popup.",
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "permissions": [
    "tabs"
  ],
  "icons": {
    "48": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{00b1b36d-a7c9-4c1d-a473-8a56bfafe568}"
    }
  }
}