What graphics framework/library do games such as Toy Bot Diaries (eg, 2D games) use that run on the iPhone? Would OpenGL, CoreGraphics, or something else be best for writing a 2D iPhone game? Thanks.
Toy Bot Diaries will certainly be using OpenGL as there's no other way to get that sort of performance on the iPhone. If you're looking to do something of that style then it's definitely OpenGL you're after.