As far as I know Apple plays pretty fast and loose with the HIG if you aren't using their UI elements. Where Apple will bust you is if you use their UI elements

As far as I know Apple plays pretty fast and loose with the HIG if you aren't using their UI elements. Where Apple will bust you is if you use their UI elements to do something that's a big stretch for the HIG. I don't play much with Android but is there anything that even approaches Flipboard? You can certainly build ugly UIs on the iPhone and get them accepted.