Examine source code of TabURL to QRCode

{
  "author": "igorlogius",
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "description": "display the active tab url as a quick response (qr) code for easy sharing between devices with a qrcode scanner",
  "icons": {
    "184": "icon.png"
  },
  "manifest_version": 2,
  "name": "TabURL to QRcode",
  "browser_action": {
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab",
    "storage",
    "menus"
  ],
  "options_ui": {
    "page": "options.html"
  },
  "version": "1.5.23",
  "browser_specific_settings": {
    "gecko": {
      "id": "{9aeca40d-0ccc-400e-9054-464403277ce1}"
    }
  }
}