Among the growing variety of Sphero apps, the worst may be the eponymous, just-updated release on iOS and Android. The update takes away some useful control options and adds game mechanics, for instance, hitting too many walls damages your Sphero's virtual shields to the point that you must stop driving so they can regenerate, that impede learning the finer points of Sphero steering.
Orbotix's Sphero Drive apps for Android and iOS and Android provide a better introduction and allow you to drive it with either joystick-esque touchscreen controls or by tilting your mobile device left, right, forward and back.
You can try out a large selection of games afterwards. For instance, one lets you play a virtual game of golf with a Sphero. Other titles flip the script by employing a Sphero as an alternate input mechanism to control a phone or tablet. An Etch-O-Matic app challenges you to draw on the screen by turning a Sphero in your hand.
This selection offers a useful reminder of this robotic ball's potential: For all its silliness, it is, in fact, a machine you can program like any other. And interesting things tend to arise from that scenario.