Startup Idea: Phone App for Scam Call Detection

Startup idea to develop a phone app that can identify and alert users of incoming calls from known scammer numbers. Additionally, the app could possibly have a feature to play an automated message or pretend the number is no longer in service.

This Idea is for something everyone could use so I give no background for myself in this case as I feel the idea speaks for itself.

A phone app that can search a incoming number number for known scammer numbers and alerts the owner, Possibly before picking up. maybe having a button with an automated message or fake number is no longer in service message. Might be serviceable just to have the button for playing a message.