We developed an extension to this basic example that consists of
a special Android application that enriches the interaction. It
provides feedback about the current state of the lamp and a subtle
indication of how the compass interface works via a round color
wheel like the one shown on the left in Figure 9. To indicate
color, the current color of the lamp is darkened—in Figure 9, the
lamp is an orange-ish red—and the circular color layout provides
an intuitive indication of what will happen when the phone is
rotated clockwise or counter clockwise. The lamp’s current color
and brightness are also written in text at the bottom of the
interface window.