The idea of this app is to draw with movement, thus you have to move to draw a line, turn, stop, etc.
Nothing new, it is like tracking GPS, but on the screen it would appear a selection of brushes, and effects, not a single 3 pixel width curve.
You can change colours, brushes, brush size.
This attributes of the brush could be in connection with the accelerometer too, to change it.
Imagine you mount the phone to your funny dog running around, and see what comes out! :-)
Target:
KIDS, definitely kids... and dogs... and cows..
What do you think?