Examine source code of Email Tracker

{
  "manifest_version": 2,
  "name": "Email Tracker",
  "description": "Free Email Tracker for Gmail",
  "version": "2.0",
  "permissions": [
    "storage",
    "https://mail.google.com/"
  ],
  "content_security_policy": "script-src 'self'; object-src 'self'",
  "web_accessible_resources": [
    "css/NoticeBorder.css",
    "css/ModalBorder.css",
    "css/jBox.css",
    "js/jquery-3.7.1.min.js",
    "js/jquery-migrate-3.4.1.min.js",
    "inboxsdk.js",
    "pageWorld.js",
    "js/myapp.js",
    "js/myapp_inc.js",
    "js/jBox.min.js",
    "js/jquery.modal.js",
    "images/new_background.svg",
    "fonts/generalsans-bold-webfont.woff2",
    "fonts/generalsans-bold-webfont.woff",
    "fonts/generalsans-medium-webfont.woff2",
    "fonts/generalsans-regular-webfont.woff2"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*"
      ],
      "css": [
        "css/NoticeBorder.css",
        "css/ModalBorder.css",
        "css/jBox.css"
      ],
      "js": [
        "js/jquery-3.7.1.min.js",
        "js/jquery-migrate-3.4.1.min.js",
        "inboxsdk.js",
        "js/myapp.js",
        "js/myapp_inc.js",
        "js/jBox.min.js",
        "js/jquery.modal.js"
      ],
      "run_at": "document_end"
    }
  ],
  "icons": {
    "16": "images/email_16.png",
    "48": "images/email_48.png",
    "128": "images/email_128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{648a3c7a-7f3b-493d-9425-def1ddd8a5d9}"
    }
  }
}