If you have a custom PCB design and you'd like to add a little Bluetooth Low Energy, this module is ultra compact and easy to use. It contains a Nordic nRF51822 Cortex M0 chip that comes integrated with BLE radio as well as most of the supporting circuitry and even a chip antenna. The whole thing is in a tin and comes with FCC, CE and TELEC certifications.
Please note! The module comes with a blank chip - this is for people who are comfortable programming the chips themselves with a J-Link programmer and the Nordic SDK. We don't provide any firmware to go along with it!
This is the same chip as the micro:bit, so there is micropython support as well as some basic Arduino support. Either way you go (SDK/micropython/Arduino) you'll still need to solder this onto a PCB and load code via a SWD programmer.