Robotics is a vast, thrilling and sometimes overwhelming interdisciplinary field involving physics, engineering, and computer science. This kit gives kids a simple, fun, and customizable introduction to robotics that lets them build eight motorized machines controlled by programs and ultrasound sensor. Kids code the programs using an easy, visual programming app on a tablet or smart phone, which connects to the robot models via a wireless Bluetooth connection. The ultrasonic sensor works on the same principle as sonar. It sends out sounds waves, which bounce off objects. The sensor interprets the echoes returning to it, and from this detects objects in the path of the sensor. After you have learned how the technology works, you can build and program your own robots using the kit's 194 building pieces. Requires a tablet or smartphone running iOS (iPhone 4s or later, iPad 3 or later, iPod 5 or later) or Android (Android 4.3 or later, on a device with Bluetooth 4.0 support).