RFduino: A finger-tip sized, Arduino compatible, wireless enabled microcontroller, low cost enough to leave in all of your projects! The RFduino has Bluetooth 4.0 Low Energy built-in, which enables it to wirelessly talk to any smartphone that has Bluetooth 4.0. Currently we have several open source apps built for the iPhone which were used in our demos. Open source Android apps are next. The RFduino has a Nordic 32 bit ARM Cortex-M0 processor, so it has more power then the UNO, however it still runs the same, simple Arduino code the UNO runs, so there is no need to learn any new programming language or environment. Your standard Arduino sketches run on the RFduino. The RFduino GPIO lines all support, Digital IO, Analog ADC, SPI, I2C, UART and PWM. There are 7 GPIO and fully software selectable and can be remapped as you wish. The RFduino is similar to the Arduino UNO or DUE, except the RFduino is a fraction of the cost and size, in addition has wireless smartphone connectivity built-in!