Examine source code of Nau Tab

{
  "manifest_version": 2,
  "name": "Nau Tab",
  "author": "Thanh Tran",
  "version": "3.0.1",
  "description": "Beautiful new tab page for modern browsers. A browser extension that will not track you.",
  "browser_specific_settings": {
    "gecko": {
      "id": "nau-tab@int3ractive.com",
      "strict_min_version": "57.0"
    }
  },
  "icons": {
    "16": "images/icon-16.png",
    "48": "images/icon-48.png",
    "128": "images/icon-128.png"
  },
  "default_locale": "en",
  "background": {
    "scripts": [
      "js/background.js"
    ]
  },
  "permissions": [
    "storage"
  ],
  "options_ui": {
    "page": "options.html",
    "chrome_style": false
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "browser_action": {
    "default_icon": {
      "16": "images/icon-16.png",
      "32": "images/icon-32.png",
      "48": "images/icon-48.png"
    },
    "default_title": "nau-tab"
  },
  "web_accessible_resources": [
    "images/icon-48.png"
  ]
}