Hold breath longer underwater

Have you ever had a vacation near the ocean where you wished you could hold your breath just a little longer to discover the wonders of the underwater world? "Hold your breath" is an iPhone exclusive training app that helps you to prolong the duration of your breath holding. The app features the two most known training methods. The first are Co2 tables that enhance your tolerance regarding Co2 levels in your blood. The second are O2 tables which help extending your maximum breath hold time. W