Some great designers around the web have released great icons, interface PSDs, and other resources that help make designing iOS apps easier. Enjoy and make sure to thank the creator of whichever resources you use!
Templates & PSDs
Icon Template
Michael Flarup’s icon template is the best one available. Very useful Photoshop actions along with some great textures.
UIButton Pack
By default UIButtons are my least favorite element in UIKit. So I made a simple button pack to fix that.
iPad GUI PSD
iPhone GUI PSD
Free App PSD
iOS Style Popover
Free Game Art
Textures & Patterns
Subtle Patterns
This is my favorite patterns website around!
Tileables
Apple iOS Linen Texture
High Resolution Fabric Texture Pack
20 Repeatable Pixel Patterns
Icons
Function Icon Set
WooFunction: 178 Amazing Web Design Icons
Fugue Icons
Not necessarily in an iOS style, but it is a huge icon set that has come in handy for me many times.
FamFamFam Silk Icons
Glyphicons
Glyphish
The Noun Project
The quality and volume of icons in The Noun Project is very impressive! They are often great to get ideas of what to represent in your icon.
Pixicus Icon Set: 106 Pixel Perfect Icons
Shock iPhone Icons
Other
Function Brush Set: 33 Subtle Grunge Textures & Effects
42 More Subtle Grunge Textured Photoshop Brushes
iOS Design Cheat Sheet
Printable iPhone Wireframe Templates
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Honourable mentioned, http://www.iconbeast.com
They have some very good iPhone icons for iOS developer.
Thanks! This is awesome
Thanks for the roundup! Bookmarked!
All wefunction.com links are 404
Great list.
Most of the icons above are indexed on Iconfinder.com
Great collection of resources but I would add Inventicons ;) They saved my day a lot of times!
Awesome man. Thanks.