Examine source code of IntSights Extend

{
  "manifest_version": 2,
  "name": "IntSights Extend",
  "short_name": "IntSights Extend",
  "version": "2.2.0",
  "description": "Fast access to highly contextual and actionable intelligence security teams can operate on.",
  "permissions": [
    "https://dashboard.intsights.com/*",
    "https://dashboard.ti.insight.rapid7.com/*",
    "tabs",
    "storage",
    "cookies"
  ],
  "browser_action": {
    "default_popup": "index.html?#/popup",
    "default_title": "IntSights Extend",
    "default_icon": {
      "16": "assets/images/logo16.png",
      "48": "assets/images/logo48.png",
      "128": "assets/images/logo128.png"
    }
  },
  "content_scripts": [
    {
      "js": [
        "contentPage.js"
      ],
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_start",
      "exclude_matches": [
        "file:///*"
      ]
    }
  ],
  "icons": {
    "16": "assets/images/logo16.png",
    "48": "assets/images/logo48.png",
    "128": "assets/images/logo128.png"
  },
  "background": {
    "scripts": [
      "backgroundPage.js"
    ],
    "persistent": true
  },
  "web_accessible_resources": [
    "assets/iframe.html",
    "assets/iframe-cve.html",
    "/assets/toaster/toaster.html",
    "assets/images"
  ]
}