private void ShowToastIfNeeded(DeckListViewModel deckListViewModel)
        {
            var  settings = ApplicationData.Current.LocalSettings;
            bool isShown;

            if (settings.Values.ContainsKey("IsEnableNotifciation"))
            {
                isShown = (bool)settings.Values["IsEnableNotifciation"];
            }
            else
            {
                settings.Values["IsEnableNotifciation"] = true;
                isShown = true;
            }

            if (!isShown)
            {
                return;
            }

            if (ToastHelper.IsAlreadyShown())
            {
                return;
            }

            string message = String.Format("You have {0} new card(s) and {1} due card(s) to review today.",
                                           deckListViewModel.TotalNewCards,
                                           deckListViewModel.TotalDueCards);
            var toast = ToastHelper.CreateToast("Review", message);

            ToastHelper.PopToast(toast);
            ToastHelper.MarkAlreadyShown();
        }