Examine source code of QR Code generator

{
  "manifest_version": 2,
  "name": "QR Code Generator",
  "version": "1.0",
  "description": "QR Code generator for current tab or custom text.",
  "icons": {
    "48": "icon.png",
    "96": "icon.png"
  },
  "permissions": [
    "tabs",
    "activeTab"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "QR Code Generator",
    "default_popup": "index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{af1465f9-a53e-463d-b164-dda1977e0650}"
    }
  }
}