I have developed an iphone graphics game using core animation. But I am not clear about how to make my application also possible to run on ipad. I know that the modification is just screen sizes and coordinates. How to modify my application so that different binaries can be generated for iphone, ipad or other apple devices from the same application? How to do it from architecture point of view? My current application architecture: A view controller handles user input (such as touches). A separate game data class is owned by view controller and holds coordinates and other game information. A view class holds layers and plays animations on these layers.