Smart Doorbell(using live streaming from Camera ) IOT app

Projects General Guidance
1

I want o implement IOT system in which Camera Doorbell live stream on person's mobile app when any person press button on camera doorbell.

CAmera doorbell connected with WiFi and in house person can be any where in house or outside but he will get notification/ring in our app so he can know some one at door and can see him and talk to him.

require help on this to achieve in cost effective way

2

Security camera for door bell (WiFi connection) - it sounds like you have this in place already.

NodeMCU or WeMOS (with WiFi built in) to monitor the button of the door bell; can send message over WiFi. I suppose there's a way to have a push notification to an Android or iOS app, but that part you'll have to research yourself.