In your Arduino application code, you will add a software serial port (aka. S3P) on two GPIOs of your microcontroller. S3P is the access way for reading and writing values in the application. The code you will need is provided in the ArdTap library in the Arduino IDE.
The TapNLink wireless module includes its own processor with an agent that you will configure with the locations of data (a.k.a. variables) that you want to view or change using your mobile HMI. You will use a free configuration software called IoTize Studio to do this.