Examine source code of WhatsApp Helper

{
  "manifest_version": 2,
  "name": "WhatsApp Helper",
  "version": "2.0",
  "description": "A extensão mais usada para otimizar o WhatsApp, envio em massa e automação inteligente via WhatsApp Web de forma rápida, prática e gratuita.",
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://web.whatsapp.com/*"
      ],
      "js": [
        "content.js",
        "contacts-exporter.js",
        "automation-esteira.js",
        "user-registration.js",
        "payment-manager.js"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "storage",
    "tabs",
    "https://olamzi.com/*"
  ],
  "background": {
    "scripts": [
      "background.js",
      "news-monitor.js"
    ],
    "persistent": true
  },
  "web_accessible_resources": [
    "automation-esteira.js"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "whatsapp-bulk@fellipmelo.com"
    }
  }
}