アプリ内にAppStoreをだいたい半分だけ表示してみる ref: http://qiita.com/takuhou/items/46571c310708b4033784

ViewController.h

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

@interface ViewController : UIViewController {
    // AppStore表示用のViewController
    SKStoreProductViewController *productViewController;
}
@end

ViewController.m

#import "ViewController.h"

@interface ViewController () <SKStoreProductViewControllerDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    productViewController = [[SKStoreProductViewController alloc] init];
    productViewController.delegate = self;

    self.modalPresentationStyle = UIModalPresentationFormSheet;
}

- (void)viewDidAppear:(BOOL)animated
{
    [self presentViewController:productViewController animated:YES completion:^() {

        NSString *productID = @"646680221";
        NSDictionary *parameters = @{SKStoreProductParameterITunesItemIdentifier:productID};
        [productViewController loadProductWithParameters:parameters
                                         completionBlock:^(BOOL result, NSError *error)
         {}];
    }];

    self.view.superview.frame = CGRectMake(0, 300, 320, 180);
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)productViewControllerDidFinish:(SKStoreProductViewController *)viewController {
    [self dismissViewControllerAnimated:YES completion:nil];
}