finalise, fix deprecation errors and update Apple app to Apple Developer

My vocal warm up app had been going for about 10 years, and now Apple insist that I update it, or they will remove it. I've managed to make some small changes, but there are a few deprecation errors showing up and I don't know how to fix them. So I need someone to check and make sure the app is clean and viable, and help me to get the updated version up to the Developer site.