The Xadow GSM+BLE module is a small board that can be used in a custom application (as well as the Seeed Xadow development family) to make phone calls, send texts, get GPS data or communicate over Bluetooth.

This is the core module used in Seeed's various RePhone kits. I picked this up from their Kickstarter a few months back, but haven't really had much of an interest in it since then. You will receive the board and user guide in the original package, but it does not come with a SIM card or cellular plan.

More information from the Seeed Studio product page:

Whether making and receiving telephone calls over a radio link using external speakers and microphone, or exchanging data in short distances with Bluetooth, you can do it with Xadow GSM+BLE.

As the heart of RePhone kit Create, the Xadow GSM+BLE is built around the powerful System-On-Chip (SOC) MT2502, offering a rich range of communication protocols - GSM, GPRS and Bluetooth (v4.0 and 2.1 dual mode). It supports quad-band 850/900/1800/1900MHz that covers any GSM network in the world. Simply insert a 2G Nano SIM card, then you are able to enchant things with cellular connectivity.