Examine source code of Mobile Platform Spoofer

{
  "name": "Mobile Platform Spoofer",
  "version": "1.3",
  "description": "Modifies the navigator.platform property while simulating a mobile viewport, allowing websites to recognize your browser as a mobile device for testing or compatibility purposes",
  "manifest_version": 2,
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "contentscript.js"
      ],
      "run_at": "document_start"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{77ce3ec8-358f-4c6b-96ab-1dc16008c20d}"
    }
  }
}