Newbie needing to know what Size PNG files and DPI to create for IPhone and IPAD App

[iphonesdkdevnewbie]

Good day iphonedevsdk. I just became a iphone developer last week. I am a graphic artist with a great idea for an iphone app. I need to know what Size PNG files to create for IPhone and IPAD App. I read that PNG files for the IPhone 4 has to have a certain DPI or it wont show up on the IPhone. Please put up with my newbie-ness for now.

[iphonesdkdevnewbie]

I need to know what size and DPI PNG files do I need to create in photoshop for my IPhone App that I am creating.

[baja_yu]

Go with default 72dpi for all images. For sizes (and many more details) read the Human Interface Guidelines and iOS Application Programming Guide in the documentation at developer.apple.com