A wandering mind can lead to many unproductive moments.  Retraining oneself to remain focused need not be as grueling as it sometimes seems.  InterAxon are the makers of Muse, the brain sensing headband.  It connects to your smartphone and guides you through mental training and exercises. The idea is to remain calm and resist distractions.  Your performance is broadcasted in real time by the sounds of a light wind.  Straying will cause these same winds to change and come across as unsettled.  The ability to progress will also reap you benefits such as tranquility and inner peace. The Muse is available in two separate colors (white and black) and can be purchased for $299.