Our priorities changed before we were able to polish this. We never did any marketing so the sales never really took off. Those who did play it loved it but felt it wasn't quite finished. A little bit of polish could take it a long way! It was developed fully natively with Objective C and OpenGL with some custom shaders for the drawing and highlighting effects. Adding the ability to save drawings, custom brushes, and better UI could make it look more polished, while saving songs to social networks could make it spread virally. We'd love to see you make this a huge success!