Harmonizer is a real-time audio pitch shifter effect that offers the ability to mix harmonies into the original signal or function as a standalone pitch shifter. This iPhone app operates as an Audio Unit plugin and can be utilized in real-time through the device's microphone or with external devices like iRig. Notably, the pitch shifting maintains the original tempo without affecting timing.

With features such as 2 harmony voices, smooth pitch shift controls in half tones and cents, adjustable volumes for the original voice and pitch-shifted voices, master reverb control, and an EFX on/off button in standalone mode, Harmonizer provides a versatile tool for musicians. Whether using headphones without a mic for acoustic instruments or singing with harmonies, this app enhances musical creativity.