Georgia and Rene checked out Ozobot at CES 2014 which are tiny autonomous robots that can follow patterns and recognize colors. That means you can also trace and draw patterns on your iPad for Ozobot to follow.
Ozobot is a multi-surface robot, which is why it can recognize colors and lines on both an LCD of an iPad or on a flash card laid on a table. The Ozobot can currently recognize over 1,000 sets of instructions. There are four free apps for both iOS and Android already available that aim to challenge Ozobots and their owners.
The Ozobot should be available soon and will retail for around $60.