Just implement a simple IBAction that you connect with your ~UIBarButton
-(IBAction)barButtonPressed {
if (yourBoolean) {
TrueViewController *trueViewController = [[TrueViewController alloc] init];
[self.navigationController pushViewController:trueViewController animated:YES];
} else {
FalseViewController *falseViewController = [[FalseViewController alloc] init];
[self.navigationController pushViewController:falseViewController animated:YES];
}