Here is a list of all files with brief descriptions:

[detail level 12]

▼ CocoaExtension
CocoaExtension.h	Unified header collection for Foundation.framework and AppKit.framework - the main parts of Cocoa - extensions
FSEventStream.h	FSEventStream wrapper in [<FSEvents.h>][0]
NSAImageWell.h	'Real' image well implementation
NSAttributedString+Cocoa.h	NSMutableAttributedString attributes dictionary and data type to support it
NSAVersion+System.h
NSControl.h	[NSControl]0] category extension collections
NSGeometry.h	Human friendly NSGeometry symbols and macros
NSImage.h	NSImage category extension collections
NSPasteboard.h	NSPasteboard category extension collections
NSTextView.h	NSTextView extension
▼ FoundationExtension
FoundationExtension.h	Unified header collection for Foundation.framework extension collection
NSAArray.h	See CoreFoundation-Subclass for concept of these objects
NSAClassDeprecated.h	Object model for Objective-C runtime Class in <objc/runtime.h>
NSACommonCrypto.h	Extension categories using CommonCrypto/CommonCryptor
NSACommonDigest.h	Extension categories using CommonCrypto/CommonDigest
NSADataObject.h	Object containers to handle various concept of data structure
NSADictionary.h	See CoreFoundation-Subclass for concept of these objects
NSAEnumerator.h	Enumerators for convinience
NSAFunctional.h	See Map/Filter/Reduce for concept of functional tools
NSAOrderedDictionary.h	Dictionary with ordered keys, guaranting its order is keeped
NSAOverridingMediator.h	Tool for partial method implementation
NSArray.h	NSArray and NSMutableArray extension cateogry collections
NSAString.h	See CoreFoundation-Subclass for concept of these objects
NSASubscript.h	Protocols to handle indexed or keyed subscript of modern Objective-C
NSAttributedString.h	NSAttributedString extension category collection
NSAVersion.h	Tool for system version
NSBundle.h	NSBundle extension cateogory collection
NSCharacterSet.h	NSCharacterSet extension cateogory collection
NSData.h	NSData extension category collection
NSDate.h	NSDate extension cateogory collection
NSDictionary.h	NSDictionary extension cateogory collection
NSJSONSerialization.h	NSJSONSerialization extension cateogory collection
NSMacro.h
NSNull.h	NSNull extension cateogory collection.
NSNumber.h	NSNumber and NSDecimalNumber extension category collection
NSNumberFormatter.h	NSNumberFormatter extension category collection
NSObject.h	NSObject or Class extension category collection. Or NSObject Protocol
NSPathUtilities.h	NSPathUtilities.h extension function collection
NSSet.h
NSString.h	NSString and NSMutableString extension category collection
NSStringEncoding.h	NSStringEncoding missing constants collection
NSTimer.h	NSTimer extension category collection
NSURL.h	NSURL extension category collection
NSURLRequest.h	NSURLRequest and NSMutableURLRequest extension category collection
NSURLRequestCreations.h	Creation category extension for various objects using NSURLRequest
NSValue.h	NSValue related extension cateogory collection
▼ UIKitExtension
NSAttributedString+UIKit.h	NSMutableAttributedString attributes dictionary and data type to support it
UIActivityIndicatorView.h
UIAlertView.h
UIAPlaceholderTextView.h
UIApplication.h	UIApplication category extension collections
UIAPreparedCellTableView.h
UIAResultDisplayController.h
UIASegmentedImageView.h
UIASubviewTableView.h
UIATableView.h
UIAView.h
UIAViewController.h
UIColor.h	UIColor shortcut method category extensions
UIControl.h
UIDevice.h	UIDevice category extension collections
UIImage.h	UIImage category extension collections
UIKitExtension.h	Unified header collection for Foundation.framework and UIKit.framework extensions
UIScrollView.h	UIScrollView extension
UITableView.h	UITableView and UITableViewCell extension
UIView.h
UIViewController.h
UIWebView.h	UIWebView extension