The GIMBAL is slave mode the controlling device is MASTER. You will connect the slave module to the BlueTooth pins RX and TX reversed on the Gimbal. Look for RX/TX on the Gimbal pins.

In terms of what modules you will want to know if the MASTER devices is BLE 4 or BlueTooth 2. For example an iPhone is BLE 4. Android could be either depending on the device.

You will need to set the baud rate of the BlueTooth modules to match the Gimbal baud rate for example 9600. Here is a link that goes into that: http://www.instructables.com/id/Add-bluetooth-to-your-Arduino-project-ArduinoHC-06/.

Here is a tutorial: http://www.dronetrest.com/t/how-to-connect-bluetooth-to-your-alexmos-brushless-gimbal-controller/292