UIButton zoomin pressed

// Scale up on button press
- (void) buttonPress:(UIButton*)button {
    button.transform = CGAffineTransformMakeScale(1.1, 1.1);
    // Do something else
}

// Scale down on button release
- (void) buttonRelease:(UIButton*)button {
    button.transform = CGAffineTransformMakeScale(1.0, 1.0);
    // Do something else
}

[btn addTarget:self action:@selector(buttonPress:) forControlEvents:UIControlEventTouchDown];
[btn addTarget:self action:@selector(buttonRelease:) forControlEvents:UIControlEventTouchUpInside];
[btn addTarget:self action:@selector(buttonRelease:) forControlEvents:UIControlEventTouchUpOutside];
[btn addTarget:self action:@selector(buttonRelease:) forControlEvents:UIControlEventTouchCancel];
[btn addTarget:self action:@selector(buttonRelease:) forControlEvents:UIControlEventTouchDragExit];