[nglevin]

I don't think there really is a clearly defined boundary here.

I've worked on projects at past jobs where the designs demanded that we duplicate the look and feel of certain iOS system APIs and programs to a T. Apple passed those through approval without making a sound about those bits.

On the other hand, Tapbots has had an app rejected in the past for using a clock icon that looked a little like Apple's[1], back in 2009. And that wasn't an exact copy.

We're not going to get an official statement from Apple on this, so the best I can suggest is to tread with caution. Better to be inspired by than to flat out copy.

[1] - http://tapbots.com/blog/app-store/a-well-timed-letter-of-rej...