The BLE shield has the function of adapting low-power Bluetooth as a serial port , which are specifically designed for Arduino boards and compatible boards, simple to use, simply connect and a ready is ready to be used.

BTBee Pro is a Bluetooth serial port module that can be compatible with shields that have XBee socket.

SparkFun Bluetooth Modem - BlueSMiRF Silver

The Bluetooth Module 4.0 BLE Micro EVB can be easily placed on your PCB card, just ignore problems such as "how to design an antenna", "how to make a bluetooth chip work" and so on. The Bluetooth 4.0 BLE Micro EVB Module is perfect for portable projects. With it, you can use Android or IOS devices to communicate with your clothes!

ITDB031 is a serial port BLE Module. It is based on TI's CC2541 BLE chip. With it, you can transfer data wirelessly and do remote control. It supports central and peripheral modes. And it supports remote control for the other side that is connected. You can also support custom commands when you combine it with other devices. BLE Bee is compatible with XBee. You can simply connect it to XBee.

Note: The serial interface is 3.3V, not the typical 5V, as with many Arduino boards.