up arrow and down arrow change pen size right and left arrows change pen colour, but the "broken" part is the change colour button because it wont change the colour of the pen... the camera on and camera off buttons do exactly what they say: they turn your camera on and off (obviously)! This way you can draw on your face without literally doing it!
Updates are coming, though, so stay tuned for more! First update when this has 5 hearts and 5 stars! and also please dont write in comments that the change colour button is broken because you know that already! if there are 10 comments that are saying that the change colour button doesn't work, commenting will be turned off and you dont want that, do you? so plz plz plz DO NOT say that!!