The concept is quite simple: put a wheeled chassis on a smart phone or iPod Touch that allows for using the device as the “brain.” But that simplicity is what makes the robot, called Romo, powerful. Since the controls are contained entirely within the phone, they can be downloaded as apps. One can add new physical capabilities to Romo -– a claw, or a scoop -– but that doesn’t require any new additions to the phone.
Also, the controls are through the headphone jack. That simplifies the design and means that the robot doesn’t need to be linked with only one brand of smart phone."
Link to Original Source