Spam/Porn blocker software for chat app

Hey All, pretty new here so hi.

I am currently in talks to develop a new chat-type social app and was wondering if anyone could recommend any third party software we could incorporate into the build for both iOS and Android which would identify and block rude pics and spambots.

Also – and please excuse my lack of knowledge – does anyone have any idea on the cost of these types of software?

Many thanks!

J