Okay, after reading into this topic, thinking and trying out, now I know how to do. I will use the default UART serial port in order to transmit the LED info.
I used a BluetoothLE scanner app in order to find out the UUIDs. After sending text to the correct UUID, I was able to see the text in the serial console output of the Arduino IDE.
Now, as I have a clue how to do, the real work begins - making everything to work with my app