Breath Training

"Practicing regular, mindful breathing can be calming and energizing and can even help with stress-related health problems ranging from panic attacks to digestive disorders."
Andrew Weil, M.D.

This App will help you regularly exercise your breathing and reap the benefits in no time. Each session is only about half a minute and can be done anywhere.
Other then training your breathing, you can check all your past sessions in full detail, including a diagram showing on which weekday you train the most.