Electronic – Arduino to Android serial communication issue

I've been trying to use this serial for android library now, but I can't make it work. I'm trying to run this little program in android:

    // MouseLib.ino
    #include "tracker.h"

    PositionTracker tracker(6,5);
    void setup() {
        Serial.begin(115200);
        tracker.init();
    }

    void loop() {
        Serial.println("?");
        delay(20);
    }

Where the tracker is as follows:

    #include "Arduino.h"
    #include "ps2.h"
    #include "tracker.h"

    PositionTracker::PositionTracker(int _clkPin, int _dPin){
        // x = y = ldX = ldY = lX = lY = 0;
        clkPin = _clkPin;
        dPin = _dPin;
        sensor = new PS2(_clkPin, _dPin);
    }

    void PositionTracker::init(){
        sensor->write(0xff);  // reset
        sensor->read();  // ack byte
        sensor->read();  // blank */
        sensor->read();  // blank */
        sensor->write(0xf0);  // remote mode
        sensor->read();  // ack
        delayMicroseconds(100);
    }

The code works fine when I plug Arduino to pc, but when i plug it in an Android device it just doesn't work. If I comment the "tracker.init()" line, it works fine for Android. If I use the example from ps2 library, it works fine as well.
Oh, and I'm using the sample app for the serial library on a Moto G. Any ideas?

Links for the libraries:

• USB Serial for Android: https://code.google.com/p/usb-serial-for-android/
• ps2.h(mouse communication): http://playground.arduino.cc/ComponentLib/Ps2mouse

EDIT

Right after posting this, I've found the issue: I was looking at the wrong website for the library. The answer was posted on their wiki already.

From the library's wiki (can't post the link, as I'm low on reputation):

Some Arduinos use the DTR line to determine serial channel readiness. In your Android code, call setDTR(true);