What device do you have? Can you give any more detail? You don't need a promo code unless you want to save.
I have an Iphone 3G, and I tried restarting the device too, but no luck. Nothing happens after the warping and m4u thingy.
Folks, I have to apologize. It does seem the app doesn't work properly on some 3G devices (but it works ok on 3G S). I've removed it from sale until I get it fixed. Sorry and thanks for your patience. Dave
Voice Changer Plus is fixed for iPhone 3G and back in the app store. It supports saving 5 messages in the free version now. Enjoy! Dave