NSString category for reversing a string.

NSString+Reversed.h

//
//  NSString+Reversed.h
//
//  Created by Bryan Luby on 5/16/13.
//

#import <Foundation/Foundation.h>

@interface NSString (Reversed)

// Reverses an NSString. Ex: "today" becomes "yadot"
+ (NSString *)bjl_reversedStringFromString:(NSString *)string;

@end

NSString+Reversed.m

//
//  NSString+Reversed.m
//
//  Created by Bryan Luby on 5/16/13.
//

#import "NSString+Reversed.h"

@implementation NSString (Reversed)

+ (NSString *)bjl_reversedStringFromString:(NSString *)string
{
    NSUInteger count = [string length];
    
    if (count <= 1) { // Base Case
        return string;
    } else {
        NSString *lastLetter = [string substringWithRange:NSMakeRange(count - 1, 1)];
        NSString *butLastLetter = [string substringToIndex:count - 1];
        return [lastLetter stringByAppendingString:[self bjl_reversedStringFromString:butLastLetter]];
    }
}

@end