The early prototype for the application made use of the Android SurfaceView, a View (classes for dealing with user interface and interaction) for drawing graphics onto the screen.
The prototype took in image files that were placed in the resources folder, and decoded them into Bitmap objects that could drawn onto the SurfaceView using the Canvas, which holds the drawing calls.
The Canvas was then used to draw the map background, and an arrow was drawn on top of that background.
A Thread was used to keep the graphics being drawn without it taking away processing from the user interface, so the application would not become unresponsive.