Shrunk down an Arduino to the size of a finger-tip. RFduino is A finger-tip sized, Arduino compatible, wireless enabled microcontroller, low cost enough to leave in all of your projects. The RFduino runs Arduino code and can do everything an Arduino can, plus much more. Using the RFduino USB shield, simply plug the RFduino into a USB port of any computer and use the Arduino IDE to load your Arduino sketch, which automatically begins running on the RFduino. Then you can detach the RFduino USB shield and plug the RFduino directly into your project. (The RFduino requires USB Shield part number RFD22121 for programming.)

Note : The RFduino requires USB Shield (RFD22121 - RFDUINO USB SHIELD) for Programming