Core Plot is a plotting framework for Mac OS X and iPhone OS. It provides 2D visualization of data, and is tightly integrated with Apple technologies like Core Animation, Core Data, and Cocoa Bindings.

This project is a simple iPhone app which displays anagrams. It's published by Bubble Pop Software and available on the iTunes App Store.

It shows how to send and process network requests via an operation queue, display a wait indicator, show and hide the keyboard while dimming the screen underneath, support auto-rotation of UI elements, open URLs, support a table view, display error alerts, do simple animations, and query for wifi availability.

GLGestureRecognizer is an Objective-C implementation of the $ 1 Unistroke Recognizer, a simple gesture recognition algorithm (see Credits below). It is made available here in the form of an iPhone application project. It was implemented over the course of a couple evenings in late April 2009 by Adam Preble.
A demo iPhone project is provided; a UIView subclass receives touch events and sends them to the GLGestureRecognizer class while drawing the touched path in white. Once the gesture is completed, the resampled gesture is shown in green, its center at the red dot, along with the name of the best match, score (lower is better), and gesture orientation. A sample size of 16 points is used in the example, which seems to be adequate for very basic shapes.

SC68 Player allows you to browse and play songs from the Atari ST SNDH YM2149 Archive on your iPhone or iPod Touch. The Atari ST music archive consists of old "chip"-music from games, and the Atari ST demo-scene that are in the public domain. A song is generally less than 10k and there is currently over 3000 songs available. Authors and songs by authors can be searched by using the quick search bar at the top of the authors list, and at the top of the authors song list. Tap the status bar to quickly scroll to the search bar.

A very cool file and contact transfer over WiFi application by Emanuele Volcano at Infinite Labs, released under BSD. Code is called "Slider" app, available on the app store as "Mover."

Framework for the iPhone that makes interacting with Ruby on Rails applications dead simple