PSTreeGraph is a tree graph view control implementation for Cocoa Touch. It is a port of the sample code from Max OS X to iOS (iPad). See WWDC 2010 Session 141, “Crafting Custom Cocoa Views”.
iOS Universal Framework is an XCode 4 project template to build universal frameworks for iOS. It adds the missing functionality for building static frameworks for iOS in Xcode 4. Universal frameworks can be used in the simulator and in iOS devices.