RedbearLab nRF51822 is an integrated "ARM + BLE4.0" development board. We have integrated Nordic nRF51822 with Freescale MK20 into a single mbed and Arduino compatible board. It is targeted for makers, engineers and students to develop low power Internet-Of-Things (IoT) projects/prototypes quickly and easily.
1. Arduino Library for nRF51822
2. Nordic nRF51822 BLE SDK
3. mbed's Bluetooth Low Energy API
We have prepared a video "Tutorial: RedBear BLE Nano Quick Start with Arduino".