I developed an iPhone module for the Coca-Cola X-Mas iPhone app. The idea of the app was to take pictures, decorate them and then upload them to the Coca-Cola X-Mas map.
I was responsible for creating the decoration part of the app. There was a drawing tool which I developed in OpenGL due to better performance and the ability to blend graphics together. The rest of the user interface and the position of the graphics is done with UIKit components.