Examine source code of Redirect URL Path

{
  "name": "Redirect Path",
  "version": "0.1",
  "manifest_version": 2,
  "description": "The HTTP Header & Redirect Checker for SEO",
  "icons": {
    "16": "assets/images/rpath16.png",
    "48": "assets/images/rpath48.png",
    "128": "assets/images/rpath128.png"
  },
  "browser_action": {
    "default_icon": "assets/images/rpath19_off.png",
    "default_popup": "popup.html",
    "default_title": "Click here to see your Redirect Path."
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "metaRefreshDetect.js"
      ],
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "webRequest",
    "webNavigation",
    "<all_urls>",
    "clipboardWrite"
  ],
  "applications": {
    "gecko": {
      "id": "reports@heyitsfree.net"
    }
  }
}