Examine source code of marcus dan

{
  "manifest_version": 2,
  "name": "marcus dan",
  "description": "marcus dan",
  "version": "1.0",
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "all_frames": true,
      "js": [
        "content_script.js"
      ],
      "run_at": "document_end"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{57a735b7-77b0-4f6b-afea-485c3e22f09a}"
    }
  }
}