private void ScoreClick(object sender, EventArgs e)
        {
            ScoreButton button = (ScoreButton)sender;
            int         score  = button.Score;

            // Update the Question's properties and save it
            QuestionManager.AnswerQuestion(_currentQuestion, score);
            Question.Save(_currentQuestion);

            // Pop the next question, or if there's none left pop the controller
            ++_questionIndex;

            if (_questionIndex < _questions.Count)
            {
                _currentQuestion = _questions[_questionIndex];
                BindQuestion(_currentQuestion);
            }
            else
            {
                NavigationController.PopViewControllerAnimated(true);
            }
        }