Examine source code of UrlParamManager

{
  "description": "View and edit GET parameters of the current page.",
  "manifest_version": 2,
  "name": "UrlParamManager",
  "version": "1.0.7resigned1",
  "applications": {
    "gecko": {
      "id": "{e4ec99dc-1652-4a7c-8a26-b912fe578996}",
      "strict_min_version": "48.0"
    }
  },
  "icons": {
    "48": "icons/urlman-48.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "browser_action": {
    "default_icon": "icons/urlman-32.png",
    "theme_icons": [
      {
        "light": "icons/urlman-32-light.png",
        "dark": "icons/urlman-32.png",
        "size": 32
      }
    ],
    "default_title": "UrlParamManager",
    "default_popup": "popup/main.html"
  }
}