I am a professional singer and lyricist (was a 2011 Grammy nominee in the Best Jazz Vocal Album category). I heard about Gary Catona from a colleague and took some Skype lessons,then a couple in person. I knew I needed to strengthen my instrument and his techniques are doing so. I recorded our lessons, but having the app is great because I dont have to listen to (mostly my own) chit-chat, just get to it. The reviewer who said the technique could be explained in three sentences is discounting how counter-intuitive these exercises can be; they were for me at first, because they involve using the back of the throat. You may crack, cough ... The videos help and once you get the idea, you have a priceless tool for improving the power and resonance of your voice, whether you sing in a belt or a whisper.