private async void Button_Click(object sender, RoutedEventArgs e)
        {
            var response = await FHClient.GetCloudRequest("sso/session/login_host", "POST", null, GetRequestParams()).ExecAsync();

            var resData = response.GetResponseAsJObject();
            var sso     = (string)resData["sso"];

            if (!string.IsNullOrEmpty(sso))
            {
                webView.Visibility = Visibility.Visible;
                webView.Navigate(new Uri(sso));
            }
        }
        private async void ShowSignedIn()
        {
            signedIn.Visibility = Visibility.Visible;
            signIn.Visibility   = Visibility.Collapsed;
            webView.Visibility  = Visibility.Collapsed;

            var response = await FHClient.GetCloudRequest("sso/session/valid", "POST", null, GetRequestParams()).ExecAsync();

            if (response.Error == null)
            {
                var data = response.GetResponseAsDictionary();
                name.Text    = string.Format("{0} {1}", data["first_name"], data["last_name"]);
                email.Text   = (string)data["email"];
                expires.Text = ((DateTime)data["expires"]).ToString();
            }
            else
            {
                await new MessageDialog(response.Error.ToString()).ShowAsync();
            }
        }