Examine source code of User-Agent Switcher and Simulator

{
  "manifest_version": 3,
  "name": "User-Agent Switcher and Simulator",
  "version": "1.3",
  "description": "Switch browser UserAgent to simulate different devices and browsers",
  "icons": {
    "16": "icons/16.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/16.png",
      "48": "icons/48.png",
      "128": "icons/128.png"
    }
  },
  "background": {
    "scripts": [
      "js/common.js",
      "js/background.js"
    ]
  },
  "permissions": [
    "storage",
    "declarativeNetRequest"
  ],
  "content_scripts": [
    {
      "all_frames": true,
      "js": [
        "js/jquery-1.10.2.min.js",
        "js/common.js",
        "js/rewriteUA.js"
      ],
      "matches": [
        "*://*/*"
      ],
      "run_at": "document_start"
    },
    {
      "all_frames": true,
      "js": [
        "js/content.js"
      ],
      "matches": [
        "*://*/*"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "js/common.js",
        "js/rewriteUserAgent.js"
      ],
      "matches": [
        "*://*/*"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "ca62c911-d9fd-42e4-b01c-d985bf965f92@useragent",
      "strict_min_version": "109.0"
    }
  },
  "host_permissions": [
    "<all_urls>"
  ]
}