A couple of extensions to NSArray that I use on a regular basis.

NSArray+JCaddons.h

//
//  NSArray+JCaddons.h
//
//  Created by Jesse Crocker on 7/26/12.
//  Copyright (c) 2012 Thisside.net. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface NSArray (JCaddons)
-(NSInteger)indexOfString:(NSString *)string;
-(NSArray *)reversedArray;
@end

@interface NSMutableArray (ShiftExtension)
-(id)shift;
-(id)pop;
- (NSMutableArray *)reversedArray;
@end

NSArray+JCaddons.m

//
//  NSArray+JCaddons.m
//
//  Created by Jesse Crocker on 7/26/12.
//  Copyright (c) 2012 Thisside.net. All rights reserved.
//

#import "NSArray+JCaddons.h"

@implementation NSArray (JCaddons)
-(NSInteger)indexOfString:(NSString *)string{
    for(int i = 0; i < self.count; i++){
        NSString *row = [self objectAtIndex:i];
        if([row isEqualToString:string])
            return i;
    }
    return -1;
}

- (NSArray *)reversedArray {
    NSMutableArray *array = [NSMutableArray arrayWithCapacity:[self count]];
    NSEnumerator *enumerator = [self reverseObjectEnumerator];
    for (id element in enumerator) {
        [array addObject:element];
    }
    return array;
}

@end


@implementation NSMutableArray (ShiftExtension)

-(id)shift {
    if([self count] < 1) return nil;
    id obj = [self objectAtIndex:0];
    [self removeObjectAtIndex:0];
    return obj;
}

-(id)pop {
    if([self count] < 1) return nil;
    id obj = [self lastObject];
    [self removeLastObject];
    return obj;
}

- (NSMutableArray *)reversedArray {
    NSMutableArray *array = [NSMutableArray arrayWithCapacity:[self count]];
    NSEnumerator *enumerator = [self reverseObjectEnumerator];
    for (id element in enumerator) {
        [array addObject:element];
    }
    return array;
}

@end\