ESRI came out with a new version that includes some really helpful ideas for us. Therefore we overworked the iPad version completely. You can see the optical result below. Doesn´t it look pretty!?
The app is still written in Objective-C and is still using ArcGIS-iOS-SDK. But as developed in the desktop version as well, there are way less FeatureLayers used now.
Also the route now is loaded as a whole at the beginning of the game and not as before where the tablet had to connect to the server after each waypoint. As a consequence the app can be used offline now.