How to tell if a message was read on iPhone with the read receipts off?

On an iPhone you have the option to let viewers see if you have read their message or not. Say I I want to know if somebody with another iPhone read my text but they had their read receipts off. How can I get past that and see if that person read the message? Is there am app for it?

You don't, there's a reason why it says "off".

I really don't think their is a way, sorry.

Nope. That isn't possible. And there won't be any apps that can tell you whether or not they read it since most apps are confined so they don't access other apps' data.

You can't