Most of us have seen those cute, tiny BB-8 robots by now. ASCAS, who happens to be a teenager, has taken the idea a step further by building a life-size BB-8 Droid that can be controlled using a smartphone. You are going to need an Arduino Uno, a HC05 Bluetooth module, a battery, an inflatable beach ball, and a few other parts to get started.
The above video shows how this BB-8 Droid works. You can find out more about the project here.