Judith Amores Fernandez, Anna Fusté Lleixà, and Jam3 created the Invisible Highway at Google Creative Lab using Unity, Tango, and the AdaBox maker kit from Adafruit.
From the YouTube description:
Invisible Highway is an experiment in controlling physical things in the real world by drawing in Augmented Reality. Simply make a pathway along the floor on your phone and the robot car will follow that path on the actual floor in your room. A custom highway with scenery is generated along the path to make the robots a little more scenic on your phone screen.
