This is part 7 and final part of the swift iOS Programming tutorials series. The first part of the series is here and the previous part of the series that is tutorial # 6 is here. In this tutorial we will finish off the app by adding two more buttons in audio playback to change the pitch of the recorded audio to make your voice sound like chipmunk and darth vader. We will learn about audio engine and some new classes in audio engine which help us to change pitch. Finally we will finish off this series by learning on how to run the app on physical device.