Interfacing Arduino Due with Android for use as a display

Hello all, first timer here. I'm just starting to use the Arduino. I'm posting this here, even though Android isn't strictly speaking a computer, because it's still interfacing with a device, and I felt it was the best place.

I've been looking at a way to use Android as a display for the board, and I found this application: Arduino Usb Android Display.

A closer look at the forum post here shows that the project uses the Usb Serial for Android library, which supposedly has support for all Arduino boards.

So I installed the application on my Nexus 5, got the USB OTG cable, and downloaded the package from here (It's the one called ArduinoUsbAndroidDisplayP.zip). The package contains the Android application's source code as well as the code for the Arduino to interface with it (the "canvas" library), and finally an example piece of code for the Arduino to draw a couple shapes on the screen. This application is in the zip file under \ArduinoUsbAndroidDisplayP\canvas\examples\simple.

I loaded this program onto the Due (after changing all WProgram.h references to Arduino.h) using the Programming Port, and then linked the Due to the OTG cable, which caused the Nexus to prompt me to open the Arduino Usb Android Display app, which I did. However, when it opens (and even after several resets of the Arduino), the screen remains as is and nothing is drawn on it, and the text still reads "No serial device." I tried my own code as well (which draws a small circle moving around on the screen), using the same canvas.h library, but still no dice.

I don't really get why it's not working; based on the forum post and the fact that the USB Serial for Android driver is supported by all Arduinos, then this should work, and it gives a powerful display for the Arduino, and one that I really need. Can anyone help with this?