With this application you can light a LED or enable a relay using an Arduino and a Bluetooth module. The application sends, when a button is pushed, a character to the Arduino microprocessor. You can light the LED by using the left side of the screen,the on and off button or you can use the toggle button on the right. You can modify the code by changing the digital pin 13 to any other pin. Or you can change the code to respond the way you prefer by changing the procedure when the Arduino receives the character H or L