Sphero Multi-Drive on Android now has an experimental feature to drive multiple Spheros at one time.
This is an experimental feature and may not work on all devices.
To connect multiple balls to your device, simply select each once from the connection screen. When you have all your balls connected, press the DONE button and start driving all of them at once. To aim each ball, you can use the regular two finger rotation gesture to aim each ball individually in a round-robin fashion or you can use the group calibrate button and align each ball by hand.
You can download it here:
iOS currently does not support connecting more than one Sphero at a time.