Interesting project in Kick Starter about the biologic-electronics interaction. In this case a cockroach controlled with your iPhone. Well it is not so complicated, but it is very exciting. A simple PCB with Bluetooth  LE (4.0 ready) module, I guess a TI CC2540, maybe from Bluegiga. Since it is BT LE, you can program any iOS device, and access to the hardware without paying the costly MFi homologation and authentication processor fees. BTW good news that Google stated that will support BT 4.0 natively, so soon available for Android I guess.