read Mac OS X developer library document on your iPhone,which includes class reference and its Properties/Class Methods/Instance Methods/Constants, Above that each contain abstract/declaration/discussion.

To be able to quickly and easily find the usage anywhere, This app is well-organized and supports very smart query, All of these are Offline reading, No internet connection required.

Covers the following libraries:

AppKit
Automator
CalendarStore
Collaboration
CoreAudioKit
CoreData
CoreLocation
DirectoryService
ExceptionHandling
Foundation
InputMethodKit
InstantMessage
PreferencePanes
QTKit
Quartz
QuartzCore
ScreenSaver
ScriptingBridge
SecurityFoundation
SecurityInterface
SyncServices
WebKit