An Arduino mini pro provides the brains. A FT-232 USB to serial board is used to program the Arduino. A standard Bluetooth module has to have HID firmware installed.

Using an HC-05 Bluetooth module, it’s possible to get this iPod-connected Arduino to relay data to and from an Android device with a small app.

Arduino developers and hobbyists who are looking for an Arduino development board that is equipped with low energy Bluetooth 4.0 connectivity might be ...

The $22 kit includes an Arduino-BLE board and 6-pin header that should be fairly broadly applicable for building Arduino-based hardware that can communicate with iOS devices.