Sphero Challenges Posted May 8, 2014 by Caldwell Public Library & filed under . When: July 1, 2014 @ 4:00 pm – 5:00 pm Repeats Sphero is the robotic ball you control with a smartphone or tablet. There are dozens of Sphero apps and challenges to direct its speed, movement and interaction with other Sphero balls. Come with friends and play on teams. No registration required.