There's a way to integrate Unity generated xcode project into another, so you could add your Unity's view as a subview of your native app.
You can find detailed instructions here: https://github.com/blitzagency/ios-unity5
It works for simple Unity app with cubes, buttons, etc. However while trying to use ImageTarget sample, Vuforia shows black screen only without any error messages in logs. Actually you can read there: Vuforia initialization successful
Has anyone tried to use Unity+Vuforia that way? Is there any fix/workaround to make Vuforia work as a referenced project from separate xcode application?
I've tried it with Unity 5.3.0f4, Xcode 7.1.1 and Image Target sample from vuforia-samples-core-unity-5-0-10