Examine source code of WeatherAPI

{
  "manifest_version": 2,
  "name": "WeatherAPI",
  "version": "1.1resigned1",
  "browser_action": {
    "default_title": "WeatherAPI",
    "default_popup": "weather.html"
  },
  "sidebar_action": {
    "default_title": "My sidebar",
    "default_panel": "weather.html"
  },
  "permissions": [
    "*://*.openweathermap.org/*",
    "webRequest"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{947e865d-f692-45bf-a2ba-a327a0d83b7d}"
    }
  }
}