"How do I get started doing extension...
saurik: to do extension development you need to be:
saurik: 1) an expert at Objective-C: this should not be your first project unless you don't expect to finish your project (which is ok, but you need to realize that)
saurik: 2) used to working on super large code bases
saurik: in essence, you are working on a large "open source" codebase (apple's program you are changing), and need to be able to make minimal hacks to it that are stable
saurik: 3) rather good at reverse engineering: you don't actually have the source code to the program you are modifying, so you are going to be staring at assembler code most of the time
saurik: (or making really good educated guesses about the frameworks, which requires an optional 4') in the historical context of apple code naming conventions)