官方接口：
1、通过appId获取信息
https://itunes.apple.com/lookup?id=应用ID
2、通过应用名称获取信息
https://itunes.apple.com/search?term=你的应用程序名称&entity=software

demo：
AFN 3.0请求代码

 AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    manager.responseSerializer.acceptableContentTypes = [NSSet setWithObjects:@"text/javascript", nil];
    
    [manager POST:@"https://itunes.apple.com/lookup?id=284910350" parameters:nil progress:nil success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {
        NSLog(@"success:%@",responseObject);
        
        
    } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
        
    }];