Rafael Hernandez has produced an excellent how-to series that will get you up and running making apps with libpd and iOS. This also includes the latest techniques and latest version of Xcode.
You can now get libpd from CocoaPods, the dependency manager for Objective-C projects: http://cocoapods.org/?q=name%3Alibpd
The libpd-based musical exploration game FRACT OSC was released last week. Congrats, Phosfiend Systems!