[Objective-C] UIViewControllerの回転を自力でやる ref: http://qiita.com/edo_m18/items/e312667396f3b49b1dbe

file0.m

AppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];

UIWindow *window = nil;

if ([appDelegate respondsToSelector:@selector(window)]) {
    window = [appDelegate window];
}
else {
    window = [[UIApplication sharedApplication] keyWindow];
}

CustomViewController *cvc = [[CustomViewController alloc] init];
[window addSubview:cvc.view];

file1.m

// CustomViewController側
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
    [UIView animateWithDuration:duration
                     animations:^{
                         CGRect frame = self.coverView.frame;
                         frame.size.width  = self.view.bounds.size.width;
                         frame.size.height = self.view.bounds.size.height;
                         self.coverView.frame  = frame;
                         self.coverView.center = self.view.center;

                         switch (toInterfaceOrientation) {
                             // 通常の状態
                             case UIInterfaceOrientationPortrait: {
                                 self.coverView.transform = CGAffineTransformMakeRotation(0);
                                 break;
                             }
                             // デバイスの左側が上の状態
                             case UIInterfaceOrientationLandscapeLeft: {
                                 self.coverView.transform = CGAffineTransformMakeRotation(-M_PI / 2);
                                 break;
                             }
                             // デバイスの右側が上の状態
                             case UIInterfaceOrientationLandscapeRight: {
                                 self.coverView.transform = CGAffineTransformMakeRotation(M_PI / 2);
                                 break;
                             }
                         }
                     }];

}