public override void ViewWillAppear(bool animated)
{
base.ViewWillAppear(animated);
btnConnectWithFacebook.Alpha = 0;
lblTitle.Alpha = 0;
lblPromise.Alpha = 0;
lblAmazingFeatures.Alpha = 0;
const double duration = 0.4;
const float delay = 0.3f;
lblTitle.FadeIn(duration, delay);
lblAmazingFeatures.FadeIn(duration, delay);
btnConnectWithFacebook.FadeIn(duration, delay + 0.5f);
lblPromise.FadeIn(duration, delay + 0.7f);
}