[IPhone] Remind to rank/review sample code

Introduction

How can we remind user to review or rank in App?
We can show a alert box to remind user to review, I writed a sample code using singleton to remind user.

How to use

[[CloudReview sharedReview]reviewFor:395519376];

CloudReview.h

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

@interface CloudReview : NSObject {
   int m_appleID;
}

+(CloudReview*)sharedReview;
-(void) reviewFor:(int)appleID;
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex;

@end

CloudReview.m

#import "CloudReview.h"


@implementation CloudReview

static CloudReview* _sharedReview = nil;

+(CloudReview*)sharedReview
{
   @synchronized([CloudReview class])
   {
       if (!_sharedReview)
           [[self alloc] init];
      
       return _sharedReview;
   }
  
   return nil;
}

+(id)alloc
{
   @synchronized([CloudReview class])
   {
       NSAssert(_sharedReview == nil, @"Attempted to allocate a second instance of a singleton.");
       _sharedReview = [super alloc];
       return _sharedReview;
   }
  
   return nil;
}

-(void)reviewFor:(int)appleID
{
   m_appleID = appleID;
   BOOL neverRate = [[NSUserDefaults standardUserDefaults] boolForKey:@"neverRate"];
   if(neverRate != YES) {
       //Show alert here
       UIAlertView *alert;
       alert = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"rate_title",@"Rate My Appication")
                                          message:NSLocalizedString(@"rate_main",@"Please Rate my Application")
                                         delegate: self
                                cancelButtonTitle:NSLocalizedString(@"rate_cancel",@"Cancel")
                                otherButtonTitles: NSLocalizedString(@"rate_now",@"Rate Now"),
                NSLocalizedString(@"rate_never",@"Never Rate"), nil];
       [alert show];
       [alert release];
   }
}
-(void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
   // Never Review Button
   if (buttonIndex == 2)
   {
       [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"neverRate"];
   }
   // Review Button
   else if (buttonIndex == 1)
   {
       [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"neverRate"];
       NSString *str = [NSString stringWithFormat:
               @"itms-apps://ax.itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?type=Purple+Software&id=%d",
               m_appleID ];
       NSLog(str);
       [[UIApplication sharedApplication] openURL:[NSURL URLWithString:str]];
   }
}

@end