Examine source code of Weather Viewer Pro

{
  "manifest_version": 2,
  "name": "Weather Viewer Pro",
  "version": "1.0.1",
  "description": "Simple weather viewer extension with live updates.",
  "permissions": [
    "tabs",
    "https://wttr.in/*"
  ],
  "browser_action": {
    "default_popup": "index.html",
    "default_icon": "icon.png"
  },
  "icons": {
    "48": "48.png",
    "128": "icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "weather-viewer-app-live@liveviewer-weather.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}