Examine source code of Unit Converter

{
  "name": "Unit Converter",
  "version": "1.2.2.1",
  "description": "Unit Converter",
  "permissions": [
    "activeTab"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "unnamed.png",
      "32": "unnamed.png",
      "48": "unnamed.png"
    }
  },
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{eafff3a8-4b7d-4357-ad3d-5ae111fa9020}"
    }
  }
}