Unity within an existing iPhone App

Is it possible to launch a game from within an app that is currently being used?

We are currently creating an app with various functionality and are interested in adding a game to the app. Is this possible?

No thats not possible.

I thought flashbangstudios made some games with interface builder menu’s, so to me it seems possible, but I don’t know much about xcode and objective c, so I’m not sure at all.

Thats a different thing.
They expanded the unity xcode project with things.

But if you have already an application you would have to rewrite it to be a unity app delegate base application so you can use unity at all.