With the USB-OTG cable, you can use your virtual pitchbend by connecting your android device to your keyboard.
With MacunDroid 1.0.3 update now, Yamaha keyboards also support it.
For use;
MIDI IN section of your keyboard midi settings
Set it to
MIDI IN CH1: Upper 1
MIDI IN CH2: Upper 2
If there is,
MIDI IN CH3: Upper3
9Apps 4.9
