If you are developing the application of RePhone based on the Eclipses IDE for RePhone
The GPIO pins can be find either on the wiki page of Xadow GSM+BLE, which is the image below,
Or get more details from the schematic of Xadow GSM+BLE.
If you are developing the application of RePhone based on the
Arduino IDE for RePhone,
we’ve done the porting from Eclipse IDE to Arduino IDE, so the ports are quite different, after the (download ) Arduino IDE for RePhone, you can find the Pin Description in the path: [i]Arduino_IDE_for_RePhone\hardware\arduino\mtk\variants\linkit_one\variant.cpp[/i]
As shown in the image below.