Examine source code of Mail Tracker Pro

{
  "manifest_version": 2,
  "name": "Mail Tracker Pro",
  "version": "1.0.0",
  "description": "Advanced email tracking extension for Gmail. Track when your emails are opened and get real-time notifications.",
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "storage",
    "activeTab",
    "notifications",
    "webRequest",
    "*://mail.google.com/*",
    "*://mail-tracker-k1hl.onrender.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_title": "Mail Tracker Pro"
  },
  "content_scripts": [
    {
      "matches": [
        "*://mail.google.com/*"
      ],
      "js": [
        "script.js"
      ]
    }
  ],
  "web_accessible_resources": [
    "index.html",
    "app.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{4683fc36-b98d-402f-8916-89a4eb18090c}"
    }
  }
}