Examine source code of WeatherCheck

{
  "manifest_version": 2,
  "name": "WeatherCheck",
  "version": "1.0",
  "description": "A simple and stylish weather add-on for your browser, allowing quick access to local weather information.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{897839fd-5f59-4741-a0cc-a0ca971506ef}"
    }
  }
}