following is code...
 In coding,there is two objective C class "InappPurchaseManager.h/InappPurchaseManager.h" and "InAppRageIAPHelper.h/InAppRageIAPHelper.m"  


 Under "Inapppurchasemanger.h"  

#import <Foundation/Foundation.h>
#import <StoreKit/StoreKit.h>

#define kProductsLoadedNotification @"ProductsLoaded"

#define kProductPurchasedNotification       @"ProductPurchased"
#define kProductPurchaseFailedNotification  @"ProductPurchaseFailed"

@interface InAppPurchaseManager : NSObject <SKProductsRequestDelegate, SKPaymentTransactionObserver>
{
    NSSet * _productIdentifiers;    
    NSArray * _products;
    NSMutableSet * _purchasedProducts;
    SKProductsRequest * _request;
}
@property (retain) NSSet *productIdentifiers;
@property (retain) NSArray * products;
@property (retain) NSMutableSet *purchasedProducts;
@property (retain) SKProductsRequest *request;

- (void)requestProducts;
- (id)initWithProductIdentifiers:(NSSet *)productIdentifiers;
- (void)buyProductIdentifier:(NSString *)productIdentifier;
@end

Under "Inapppurchasemanger.m"


@implementation InAppPurchaseManager

@synthesize productIdentifiers = _productIdentifiers;
@synthesize products = _products;
@synthesize purchasedProducts = _purchasedProducts;
@synthesize request = _request;

- (id)initWithProductIdentifiers:(NSSet *)productIdentifiers 
{
    if ((self = [super init])) 
    {
        
        // Store product identifiers
        _productIdentifiers = [productIdentifiers retain];
        
        // Check for previously purchased products
        NSMutableSet * purchasedProducts = [NSMutableSet set];
        for (NSString * productIdentifier in _productIdentifiers) {
            BOOL productPurchased = [[NSUserDefaults standardUserDefaults] boolForKey:productIdentifier];
            if (productPurchased) {
                [purchasedProducts addObject:productIdentifier];
                NSLog(@"Previously purchased: %@", productIdentifier);
            }
            NSLog(@"Not purchased: %@", productIdentifier);
        }
        self.purchasedProducts = purchasedProducts;
        
    }
    return self;
}

- (void)requestProducts 
{
    
    self.request = [[[SKProductsRequest alloc] initWithProductIdentifiers:_productIdentifiers] autorelease];
    _request.delegate = self;
    [_request start];
    
}

- (void)productsRequest:(SKProductsRequest *)request didReceiveResponse:(SKProductsResponse *)response 
{
    
    NSLog(@"Received products results...");   
    self.products = response.products;
    self.request = nil;    
    
    [[NSNotificationCenter defaultCenter] postNotificationName:kProductsLoadedNotification object:_products];    
}

- (void)recordTransaction:(SKPaymentTransaction *)transaction {    
    // Optional: Record the transaction on the server side...    
}

- (void)provideContent:(NSString *)productIdentifier
{
    
    NSLog(@"Toggling flag for: %@", productIdentifier);
    [[NSUserDefaults standardUserDefaults] setBool:TRUE forKey:productIdentifier];
    [[NSUserDefaults standardUserDefaults] synchronize];
    [_purchasedProducts addObject:productIdentifier];
    
    [[NSNotificationCenter defaultCenter] postNotificationName:kProductPurchasedNotification object:productIdentifier];
    
}

- (void)completeTransaction:(SKPaymentTransaction *)transaction
{
    
    NSLog(@"completeTransaction...");
    
    [self recordTransaction: transaction];
    [self provideContent: transaction.payment.productIdentifier];
    [[SKPaymentQueue defaultQueue] finishTransaction: transaction];
    
}

- (void)restoreTransaction:(SKPaymentTransaction *)transaction
{
    
    NSLog(@"restoreTransaction...");
    
    [self recordTransaction: transaction];
    [self provideContent: transaction.originalTransaction.payment.productIdentifier];
    [[SKPaymentQueue defaultQueue] finishTransaction: transaction];
    
}

- (void)failedTransaction:(SKPaymentTransaction *)transaction 
{
    
    if (transaction.error.code != SKErrorPaymentCancelled)
    {
        NSLog(@"Transaction error: %@", transaction.error.localizedDescription);
    }
    
    [[NSNotificationCenter defaultCenter] postNotificationName:kProductPurchaseFailedNotification object:transaction];
    
    [[SKPaymentQueue defaultQueue] finishTransaction: transaction];
    
}

- (void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transactions
{
    for (SKPaymentTransaction *transaction in transactions)
    {
        switch (transaction.transactionState)
        {
            case SKPaymentTransactionStatePurchased:
                [self completeTransaction:transaction];
                break;
            case SKPaymentTransactionStateFailed:
                [self failedTransaction:transaction];
                break;
            case SKPaymentTransactionStateRestored:
                [self restoreTransaction:transaction];
            default:
                break;
        }
    }
}


- (void)dealloc
{
    [_productIdentifiers release];
    _productIdentifiers = nil;
    [_products release];
    _products = nil;
    [_purchasedProducts release];
    _purchasedProducts = nil;
    [_request release];
    _request = nil;
    [super dealloc];
} 

under "InAppRageIAPHelper.h" 

#import <Foundation/Foundation.h>
#import "InAppPurchaseManager.h"


@interface InAppRageIAPHelper : InAppPurchaseManager
{
    
}
+(InAppRageIAPHelper *) sharedHelper;


@end


under "InAppRageIAPHelper.h" 

#import "InAppRageIAPHelper.h"

@implementation InAppRageIAPHelper
static InAppRageIAPHelper * _sharedHelper;

+ (InAppRageIAPHelper *) sharedHelper 
{
    
    if (_sharedHelper != nil) {
        return _sharedHelper;
    }
    _sharedHelper = [[InAppRageIAPHelper alloc] init];
    return _sharedHelper;
    
}

- (id)init 
{
    NSSet *productIdentifiers = [NSSet setWithObject:@"com.phoenixsports.Ats80Club.ATSStats1" ];

////    NSSet *productIdentifiers = [NSSet setWithObjects:
//                                 "com.phoenixsports.Ats80Club.ATSStats1"];
//    
    if ((self = [super initWithProductIdentifiers:productIdentifiers])) {                
        
    }
    return self;
    
}
@end

and i want to display that Auto-renewble-Subscription on my login view controller for that i write following code in may login view controller 


- (void)viewWillAppear:(BOOL)animated
{
	txt_UserName.text=@"";
	txt_Password.text=@"";
    
    
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(productsLoaded:) name:kProductsLoadedNotification object:nil];
    
//    Reachability *reach = [Reachability reachabilityForInternetConnection];	
//    NetworkStatus netStatus = [reach currentReachabilityStatus];    
//    if (netStatus == NotReachable)
    
    Connection=[[NetworkConnection alloc]initConnection];
	if (Connection.isReachable)
    {  
        if ([InAppRageIAPHelper sharedHelper].products == nil) 
        {
            
            [[InAppRageIAPHelper sharedHelper] requestProducts];
            self.hud = [MBProgressHUD showHUDAddedTo:self.navigationController.view animated:YES];
            _hud.labelText = @"Loading";
            [self performSelector:@selector(timeout:) withObject:nil afterDelay:30.0];
            
        }        

             
    } 
    else 
    {        
          NSLog(@"No internet connection!"); 
    }
 
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(productPurchased:) name:kProductPurchasedNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector: @selector(productPurchaseFailed:) name:kProductPurchaseFailedNotification object: nil];
    
}
- (void)dismissHUD:(id)arg 
{
    
    [MBProgressHUD hideHUDForView:self.navigationController.view animated:YES];
    self.hud = nil;
    
}

- (void)productsLoaded:(NSNotification *)notification 
{
    
    [NSObject cancelPreviousPerformRequestsWithTarget:self];
    [MBProgressHUD hideHUDForView:self.navigationController.view animated:YES];
    
    
}

- (void)timeout:(id)arg 
{
    
    _hud.labelText = @"Timeout!";
    _hud.detailsLabelText = @"Please try again later.";
//    _hud.customView = [[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"37x-Checkmark.jpg"]] autorelease];
	_hud.mode = MBProgressHUDModeCustomView;
    [self performSelector:@selector(dismissHUD:) withObject:nil afterDelay:3.0];
    
}
- (void)productPurchased:(NSNotification *)notification 
{
    
    [NSObject cancelPreviousPerformRequestsWithTarget:self];
    [MBProgressHUD hideHUDForView:self.navigationController.view animated:YES];    
    
    NSString *productIdentifier = (NSString *) notification.object;
    NSLog(@"Purchased: %@", productIdentifier);
    
    
    
}

- (void)productPurchaseFailed:(NSNotification *)notification 
{
    
    [NSObject cancelPreviousPerformRequestsWithTarget:self];
    [MBProgressHUD hideHUDForView:self.navigationController.view animated:YES];
    
    SKPaymentTransaction * transaction = (SKPaymentTransaction *) notification.object;    
    if (transaction.error.code != SKErrorPaymentCancelled) {    
        UIAlertView *alert = [[[UIAlertView alloc] initWithTitle:@"Error!" 
                                                         message:transaction.error.localizedDescription 
                                                        delegate:nil 
                                               cancelButtonTitle:nil 
                                               otherButtonTitles:@"OK", nil] autorelease];
        
        [alert show];
    }
    
}

// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad 
{
	
//    NSLog(@"Buying %@...", productIdentifier);
    
    SKPayment *payment = [SKPayment paymentWithProductIdentifier:@"com.phoenixsports.Ats80Club.ATSStats1"];
    [[SKPaymentQueue defaultQueue] addPayment:payment];

    [super viewDidLoad];
}


- (void)purchaseProUpgrade 
{
	NSLog(@"purchaseProUpgrade");
	
	
	SKPayment *payment = [SKPayment paymentWithProductIdentifier:@"com.phoenixsports.Ats80Club.ATSStats1"];	
	//SKPayment *payment = [SKPayment paymentWithProductIdentifier:product.identifier];
	[[SKPaymentQueue defaultQueue] addPayment:payment];
}

//
// saves a record of the transaction by storing the receipt to disk
//
- (void)recordTransaction:(SKPaymentTransaction *)transaction {
	NSLog(@"recordTransaction");
	
	if ([transaction.payment.productIdentifier isEqualToString:@"com.phoenixsports.Ats80Club.ATSStats1"]) 
    {
		// save the transaction receipt to disk
		
		
	}
}

//
// enable pro features
//
- (void)provideContent:(NSString *)productId {
	NSLog(@"provideContent");
	
	if ([productId isEqualToString:@"com.phoenixsports.Ats80Club.ATSStats1"]) 
    {
		// enable the pro features
		/* [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"isProUpgradePurchased" ];
		 [[NSUserDefaults standardUserDefaults] synchronize];*/
	}
}

//
// removes the transaction from the queue and posts a notification with the transaction result
//
- (void)finishTransaction:(SKPaymentTransaction *)transaction wasSuccessful:(BOOL)wasSuccessful
{
	
	NSLog(@"finishTransaction");
	// remove the transaction from the payment queue.
	[[SKPaymentQueue defaultQueue]finishTransaction:transaction];
	
	NSDictionary *userInfo = [NSDictionary dictionaryWithObjectsAndKeys:transaction, @"transaction" , nil];	
	
	if (wasSuccessful) 
    {
		// send out a notification that we’ve finished the transaction
        [[NSNotificationCenter defaultCenter] postNotificationName:@"InAppPurchaseManagerTransactionSucceededNotification" object:self userInfo:userInfo];
    }
    else
    {
        // send out a notification for the failed transaction
		
		UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Alert" message:@"Transation falied. Please try again." delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
		[alert show];
		[alert release];
        [[NSNotificationCenter defaultCenter] postNotificationName:@"InAppPurchaseManagerTransactionFailedNotification" object:self userInfo:userInfo];
    }
}

//
// called when the transaction was successful
//
- (void)completeTransaction:(SKPaymentTransaction *)transaction
{
	NSLog(@"completeTransaction");
	
    [self recordTransaction:transaction];
    //[self provideContent:transaction.payment.productIdentifier];
    [self finishTransaction:transaction wasSuccessful:YES];
} 

//
// called when a transaction has been restored and and successfully completed
//
- (void)restoreTransaction:(SKPaymentTransaction *)transaction
{
	NSLog(@"restoreTransaction");
    [self recordTransaction:transaction.originalTransaction];
    //[self provideContent:transaction.originalTransaction.payment.productIdentifier];
    [self finishTransaction:transaction wasSuccessful:YES];
}

//
// called when a transaction has failed
//
- (void)failedTransaction:(SKPaymentTransaction *)transaction
{
	
	NSLog(@"failedTransaction");
    if (transaction.error.code != SKErrorPaymentCancelled)
    {
        // error!
        [self finishTransaction:transaction wasSuccessful:NO];
    }
    else
    {
        // this is fine, the user just cancelled, so don’t notify
        [[SKPaymentQueue defaultQueue] finishTransaction:transaction];
    }
}
- (void)paymentQueue:(SKPaymentQueue *)queue updatedTransactions:(NSArray *)transactions
{
	
	NSLog(@"updatedTransactions");
    for (SKPaymentTransaction *transaction in transactions)
    {
        switch (transaction.transactionState)
        {
            case SKPaymentTransactionStatePurchased:
				NSLog(@"completeTransaction");
                [self completeTransaction:transaction];
                break;
            case SKPaymentTransactionStateFailed:
				NSLog(@"failedTransaction");
                [self failedTransaction:transaction];
                break;
            case SKPaymentTransactionStateRestored:
				NSLog(@"restoreTransaction");
                [self restoreTransaction:transaction];
                break;
            default:
                break;
        }
    }
} 


And in my AppDelegate.m i write following line of code in " didFinishLaunchingWithOptions" method 

[[SKPaymentQueue defaultQueue] addTransactionObserver:[InAppRageIAPHelper sharedHelper]];


With the help of following Link :- 
http://www.raywenderlich.com/2797/introduction-to-in-app-purchases