VirSyn, makers of Addictive Synth, iVoxel, and iSyn, have a new vocal harmonizer app. Harmony Voice is available now on iTunes. Thanks to reader Nique for the heads-up on this!
Harmony Voice is a pitch shifter and harmonizer with professional features including automatic tuning correction.• Four part realtime Harmonizer / Pitch corrector
• Play background track from your iTunes library.
• Hi-end Reverb, Chorus and Delay effects.
• CoreMIDI compatible for MIDI Keyboard.
• Upload to SoundCloud and File Export.
• Audio pasteboard for exchange with other Apps
Headphones are required to avoid feedback. Headsets with mic work great, for best quality we recommend IK Multimedia's iRig Mic.
They've also put out a demo to give you an idea of what it can do.