Smule has the I Am T-Pain (iTune Link) on the iTunes App Store for $0.99 (2.99 – 75%) for a limited time.

I Am T-Pain gives you Auto-Tune in the palm of your hand, using the same Antares audio technology T-Pain himself uses in the studio to record his music. Launch the I Am T-Pain app, select your favorite track, and just sing into the Mic on your iPhone. I Am T-Pain will record your new song. Then, with a single button, publish your song over email, Facebook, or MySpace. You can also select the Freestyle option and use Auto-Tune for singing without companion tracks. Use this option if you simply want to send someone an Auto-Tuned greeting over email.