Examine source code of WhatsApp Message Sender

{
  "manifest_version": 2,
  "name": "__MSG_app_name__",
  "version": "1.22",
  "description": "__MSG_app_tagline__",
  "default_locale": "en",
  "icons": {
    "48": "src/images/icons/mipmap-mdpi/icon.png",
    "72": "src/images/icons/mipmap-hdpi/icon.png",
    "96": "src/images/icons/mipmap-xhdpi/icon.png",
    "144": "src/images/icons/mipmap-xxhdpi/icon.png",
    "192": "src/images/icons/mipmap-xxxhdpi/icon.png"
  },
  "browser_action": {
    "default_title": "__MSG_app_name__",
    "default_icon": {
      "48": "src/images/icons/mipmap-mdpi/icon.png",
      "72": "src/images/icons/mipmap-hdpi/icon.png",
      "96": "src/images/icons/mipmap-xhdpi/icon.png",
      "144": "src/images/icons/mipmap-xxhdpi/icon.png",
      "192": "src/images/icons/mipmap-xxxhdpi/icon.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.whatsapp.com/*",
        "*://*.elcreative.org/*"
      ],
      "js": [
        "dist/scripts/script.min.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "dist/scripts/background.min.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "whatsapp-message-sender@elcreative.net",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "tabs",
    "activeTab",
    "storage"
  ]
}