The iPhone native portion of the MIT Mobile Framework
tap + haiku = tapku, a well crafted open source iOS framework for iPhone & iPad
Many usefull classes for iPhone applications
A minimal iPhone project template for Xcode 4
A streaming audio player class (AudioStreamer) for Mac OS X and iPhone.
A simple iPhone forms library
cocos2d for android, based on cocos2d-android-0.82, and now ported from cocos2d-iphone 0.99.4. The googlecode address is here: http://code.google.com/p/cocos2d-android-1/ . There are several demos to watch.
Part of the QuasiStep, a loose collection/library of utilities, controls and other helpers for iOS (iPhone, iPod Touch, iPad) development.
A wrapper for the iPhone's C-based AddressBook framework.
Unified cross-platform iPhone Makefile system
An iPhone map app to check the status of Paris public bicycle stations(Which is called Vélib)
Demo of using MKOverlayView (iOS 4.0) to render custom tile server overlays in a native iPhone app.
Library of components and shared code for applications targetted toward the iPhone OS.
An mp3 streaming Application for the iPhone and the iPad
iPhone client for Geoloqi
Convenience Classes for development iPhone software. Currently focusing to the Core Data Utilities. It enables you to create and search EO easily.
A jQuery plugin for mobile web development on iPhone, Android, and other small-screen WebKit devices.
Easy to use CFNetwork wrapper for HTTP requests, Objective-C, Mac OS X and iPhone
Library for the creation of HUDs in iPhone applications.
cocos2d for iPhone
An Example XCode-Project with comiled OpenSSL for iOS Devices (iPhone, iPod Touch, iPad)
iPhone tracking library for Mixpanel Analytics
Script and instructions to compile imagemagick as a static library to use in any iPhone project
iPhone app for testing the x-callback-url interapp communication protocol
OmniGraffle design stencils for designing iOS applications for iPhone, iPad and iPod touch devices.
iUnitTest is an unit testing framework for iPhone applications.
iPhone utilities mostly for Core Animation
A simple class for listening to microphone levels, suitable for the iPhone.