iPad and iPhone layout helper
There are several helper tools for developing an iOS app - but in my opinion these 3 are really amazing:
LiveView
LiveView is a specialized remote screen viewing application intended as a tool to help designers create graphics for mobile applications, it has also proven to be useful for creating quick and dirty simulations, demos, and experience prototypes.
iPhone/iPad GUI Templates
http://www.teehanlax.com/downloads/ipad-gui-psd/
