Examine source code of Link Redirect Trace

{
  "manifest_version": 2,
  "name": "Link Redirect Trace",
  "short_name": "Redirect Trace",
  "description": "The all-in-one redirect path analyzer. HTTP Headers, Rel-Canonicals, robots.txt, link power, trust and risk analyzed, too!",
  "version": "0.9.13.2resigned1",
  "version_name": "0.9.13.1 BETA",
  "icons": {
    "19": "/img/icon19.png",
    "38": "/img/icon38.png",
    "128": "/img/icon128.png",
    "256": "/img/icon256.png"
  },
  "browser_action": {
    "default_icon": "/img/icon19.png",
    "default_popup": "/html/popup.html"
  },
  "background": {
    "scripts": [
      "/lib/jquery-3.3.1.min.js",
      "/js/Cache.js",
      "/js/Tracer.js",
      "/js/Path.js",
      "/js/Hop.js",
      "/js/RobotsTxt.js",
      "/js/UrlChecker.js",
      "/js/Warning.js",
      "/js/Icon.js",
      "/js/SearchEngines.js",
      "/js/RobotsImg.js",
      "/js/RTIcon.js",
      "/js/lrt/LRT.js",
      "/js/IP.js",
      "/js/Screenshot.js",
      "/js/App.js",
      "/js/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "http://*/*",
        "https://*/*"
      ],
      "js": [
        "/js/cs-page.js"
      ],
      "run_at": "document_start"
    }
  ],
  "web_accessible_resources": [
    "/img/*"
  ],
  "permissions": [
    "<all_urls>",
    "activeTab",
    "tabs",
    "http://*/*",
    "https://*/*",
    "webRequest",
    "webNavigation",
    "storage",
    "downloads"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{5327e982-d0be-4b85-b661-dba2ef210ab8}"
    }
  }
}