Let's get an update about chat apps like WhatsApp technologies and their monetization models. Contus Fly helps to build a messaging app like WhatsApp in both mobile and web.
Technologies Involved:
Erlang
Ejabberd
XMPP
NoSQL
YAWS
PHP
Amazon S3 Bucket
To check more: https://www.apptha.com/blog/build-chat-app-like-whatsapp/