Can I mirror my iPhone display onto my iPad?

I have used Airplay successfully with Apple TV but if I want to demonstrate using an app to a prospective customer/s outside the boardroom is there a way of mirroring my iPhone to my iPad rather than having people huddle around my iPhone screen? I know Airplay currently doesn't support this feature but I am hoping there is an app out there that does. Air Display by Avatron seems to be the closest thing in the App Store but it looks like it is only designed to be a mirror of PC. To iPad screen.