Examine source code of Opener Detector

{
  "manifest_version": 2,
  "name": "Opener Detector",
  "version": "1.0.1resigned1",
  "description": "Checks for window.opener vulnerabilities as you browse.",
  "homepage_url": "https://github.com/HarryCutts/opener-detector",
  "icons": {
    "48": "icons/icon.png",
    "96": "icons/icon@2x.png"
  },
  "permissions": [
    "storage"
  ],
  "options_ui": {
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "lib/browser-polyfill.min.js",
        "config.js",
        "check.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "vuln_report_page.html"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{38554d36-f61e-4120-9573-1f83fa991681}"
    }
  }
}