ExpandButtonTriggerAction.cs

 public class ExpandButtonTriggerAction: TriggerAction<Button>
    {
        protected async override void Invoke(Button button)
        {
            await button.ScaleTo(0.95, 50, Easing.CubicOut);
            await button.ScaleTo(1, 50, Easing.CubicIn);
        }
    }