Examine source code of siteGrabber

{
  "manifest_version": 2,
  "name": "siteGrabber",
  "version": "0.1.89",
  "description": "Download whole content of a website.",
  "icons": {
    "48": "style/grabber.svg"
  },
  "permissions": [
    "<all_urls>",
    "tabs",
    "activeTab",
    "storage",
    "unlimitedStorage"
  ],
  "background": {
    "scripts": [
      "js/ext/jszip.js",
      "js/iconAnimator.js",
      "js/db.js",
      "js/clsProject.js",
      "js/projectManager.js"
    ]
  },
  "browser_action": {
    "browser_style": true,
    "default_popup": "windows/new.html",
    "default_icon": "style/grabber.svg",
    "default_title": "SiteGrabber"
  }
}