CityEngine combined with Unity and a tablet – iOS requires a developers account, Android simple needs the 30 days Unity trial – allows city wide models to run with a touch based interface.
The movie below shows the app so far:
See also – Trail Rending of Agents with NavMesh, Physics, Unity and CityEngine, Augmented Reality City Table Top – Unity, CityEngine and Vufoira and Shortest Path Modelling and NavMesh in Unity and CityEngine.