Good exercises, but theres plenty of room to improve the app

Very good concept, but the UI could be much better, it feels "underworked" for the price. It doesnt feel like a $4.99 app. It would be much better if the app follows the iOS design guidelines, and make the app retina ready, pleasing to the eye.
The video instructions could be more detailed where you can actually see the instructor doing the exercise up close, rather than far away in a wide room behind a piano.
The audio samples are good, but its distracting to hear the instructor doing the whole exercise. Would be better if he does the first round and then just plays the piano to make it easier to follow the music.

Bezaleel31 about VoixTek Voice Training