This app opens on a blank page. When you draw on the page with your finger the app records whatever sound is around. The color that is drawn is related to pitch and the size of the line is related to the relative dynamic.
Today I tried this app with a group of first graders. We're practicing matching pitch and getting into the head voice with some octave low high low oooooo sounds. I sang and drew a line going up and down following the contour. Because I sang an octave, the starting color, high point, and ending color are all the same. The kids echoed my voice and I drew while they sang, again following a contour. They could visually see where they had sung the same pitch as me and where they had a different pitch because the colors were different.