private async void ImageButton_Clicked(object sender, EventArgs e)
{
textBox.Text = "Hello world!";
ViewExtensions.FadeTo(sky, 0.2, 2000);
await ViewExtensions.TranslateTo(button, 200, 0, 500);
await ViewExtensions.RotateYTo(button, 0, 500);
await ViewExtensions.TranslateTo(button, -200, 0, 500);
await ViewExtensions.RotateYTo(button, 180, 500);
ViewExtensions.FadeTo(sky, 1.0, 2000);
}