Joystick BT Commander is working perfectly with the LG G2 phone, the Adafruit EZ-link 315a bluetooth, and the Parallax Quickstart demo board.
Nice to hear, I started learning microcontrollers with Basic Stamps 
http://forums.parallax.com/showthread.php/103850-Yet-another-balancing-robot?daysprune=-1
Not sure what "Data XXX" is used for. Is there any chance the MCU can send and display a serial message in your APP?
YES !!! see reply #74
Joystick BT Commander listens to the MCU and expect a 4 Byte data frame
<STX button status Byte data Byte (your choice) ETX>
This is the relevant code snippet in the Arduino demo sketch (V10.3):
mySerial.write(STX); mySerial.write((button<<2)+4); mySerial.write(data+4); mySerial.write(ETX); // +4: avoid 0x2 & 0x3
There is another version with 4 data bytes and 6 buttons
For those interested, contact me via PM
The joystick image is displayed a little above center but that's okay
I need that type of feedback, please let me have a screen shot of the App on your LG G2 phone