应该评分跳转：

  https://itunes.apple.com/WebObjects/MZStore.woa/wa/viewContentsUserReviews?id=8888888888&pageNumber=0&sortOrdering=2&type=Purple+Software&mt=8

应用下载跳转：

  https://itunes.apple.com/cn/app/id8888888888

第二种方式

  先导入StoreKit.framework 
//初始化控制器 
SKStoreProductViewController *storeProductViewContorller = [[SKStoreProductViewController alloc] init];
//设置代理请求为当前控制器本身
storeProductViewContorller.delegate = self;
//加载一个新的视图展示
  [storeProductViewContorller loadProductWithParameters:
   //appId唯一的
   @{SKStoreProductParameterITunesItemIdentifier : APP_ID} completionBlock:^(BOOL result, NSError *error) {
 //block回调
 if(error){
   NSLog(@"error %@ with userInfo %@",error,[error userInfo]);
 }else{
   //模态弹出appstore
   [self presentViewController:storeProductViewContorller animated:YES completion:^{
    
   }
    ];
 }
   }]

  //代理事件
  #pragma mark-SKStoreProductViewControllerDelegate
  - (void)productViewControllerDidFinish:(SKStoreProductViewController *)viewController{
[self dismissViewControllerAnimated:YES completion:^{
  
}];
  }