// AppDelegate.h
#import <UIKit/UIKit.h>
#import "TopViewController.h"

// UINavigationControllerのインスタンス追加
@interface AppDelegate : UIResponder <UIApplicationDelegate> {
  UINavigationController *naviController;
  TopViewController *topController;
}

@property (strong, nonatomic) UIWindow *window;

@end

// AppDelegate.m
#import "SampleAppDelegate.h"

@implementation SampleAppDelegate

@synthesize window;

- (void)applicationDidFinishLaunching:(UIApplication *)application
{
    self.window = [[UIWindow alloc]initWithFrame:[[UIScreen mainScreen]bounds]];

    topController = [[TopViewController alloc] init];
    naviController = [[UINavigationController alloc] initWithRootViewController:topController];

    [self.window addSubview:naviController.view];

    [self.window makeKeyAndVisible];
}

@end

// 遷移前 TopViewController.h
#import <UIKit/UIKit.h>

#import "NextViewController.h"

// 遷移後のインスタンス追加
@interface ViewController : UIViewController {
  SecondViewController *secondController;
}

@end

// 遷移前 TopViewController.m
- (void)viewDidLoad
{
    [super viewDidLoad];

    // UINavigationBar hidden = YES
    self.navigationController.navigationBar.hidden = YES;

}

- (void)tapAction
{
    // 適当な場所に画面遷移をおく
    secondController = [[NextViewController alloc] init];
    [self.navigationController pushViewController:secondController animated:YES];
}