An important Caveat is Section 1 and 10.1: The Human Interface Guidelines. This is large document that describes in general the "look and feel" of apps that run

An important Caveat is Section 1 and 10.1: The Human Interface Guidelines. This is large document that describes in general the "look and feel" of apps that run on the iPhone. If you make something that doesn't fit with their long-term vision, or irks them in some other way, it is extremely easy for them to say "You are violating the Human Interface Guidelines," and leave it at that. This has prevented me from delivering innovative UI experiences on iOS, stifling creativity, and again, frustrating developers with wasted research and development time.