A simple way to create or schedule a timer that doesn't retain its target.

NSTimer+WeakTarget.h

//
//  NSTimer+WeakTarget.h
//
//  Created by Maksym Huk on 4/8/13.
//  Copyright (c) 2013 Maksym Huk. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface NSTimer (WeakTarget)

+ (NSTimer *)timerWithTimeInterval:(NSTimeInterval)ti weakTarget:(id)aTarget selector:(SEL)aSelector userInfo:(id)userInfo repeats:(BOOL)yesOrNo;
+ (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)ti weakTarget:(id)aTarget selector:(SEL)aSelector userInfo:(id)userInfo repeats:(BOOL)yesOrNo;

@end

NSTimer+WeakTarget.m

//
//  NSTimer+WeakTarget.m
//
//  Created by Maksym Huk on 4/8/13.
//  Copyright (c) 2013 Maksym Huk. All rights reserved.
//

#import "NSTimer+WeakTarget.h"

@interface WeakTimerTarget : NSObject

@property (weak, nonatomic) id target;
@property (nonatomic) SEL action;

- (id)initWithTarget:(id)target action:(SEL)action;
- (void)action:(id)sender;

@end

@implementation WeakTimerTarget

- (id)initWithTarget:(id)target action:(SEL)action
{
    if (self = [super init]) {
        self.target = target;
        self.action = action;
    }
    return self;
}

- (void)action:(id)sender;
{
    [_target performSelector:_action withObject:sender];
}

@end

@implementation NSTimer (WeakTarget)

+ (NSTimer *)timerWithTimeInterval:(NSTimeInterval)ti weakTarget:(id)aTarget selector:(SEL)aSelector userInfo:(id)userInfo repeats:(BOOL)yesOrNo
{
    return [self timerWithTimeInterval:ti target:[[WeakTimerTarget alloc] initWithTarget:aTarget action:aSelector] selector:@selector(action:) userInfo:userInfo repeats:yesOrNo];
}

+ (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)ti weakTarget:(id)aTarget selector:(SEL)aSelector userInfo:(id)userInfo repeats:(BOOL)yesOrNo
{
    return [self scheduledTimerWithTimeInterval:ti target:[[WeakTimerTarget alloc] initWithTarget:aTarget action:aSelector] selector:@selector(action:) userInfo:userInfo repeats:yesOrNo];
}

@end