Examine source code of Mini Weather Panel

{
  "manifest_version": 2,
  "name": "Mini Weather Panel",
  "version": "1.0",
  "description": "Check weather for your saved cities instantly.",
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "weather-mini@part3",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "48": "sun-48.png",
    "96": "sun-96.png"
  },
  "browser_action": {
    "default_title": "Mini Weather",
    "default_popup": "forecast/weather-panel.html",
    "default_icon": {
      "48": "sun-48.png",
      "96": "sun-96.png"
    }
  }
}