This app acts like a serial monitor, one which you use in Arduino IDE for transmitting and receiving characters through serial devices.
You can use this app for transferring characters to Arduino, raspberry pi or other microcontrollers through Bluetooth connection.
Steps to connect>
1.Pre-pair your Bluetooth device with your android phone.
2. Open app and click on bluetooth icon.
3.Select your bluetooth device from the list.
4. Once bluetooth signals to green icon in app, your device is ready for communication.