Eventide released QVox, their 6th iOS plugin! QVox takes your audio input and split it up into 4 different voices that you can widen and manipulate. There's also a bunch of pitch stuff in here, all of which can be locked to a key or scale. QVox is AUv3 and Inter-App Audio compatible.
QVox App Store Description:QVox is a creative audio effect that transforms vocals, guitars, drums, and synths into four independent voices. Create beautiful harmonies, widen instruments and design groovy rhythmic sequences with diatonic pitch shifting and delay. You can choose the key, scale, and each voice’s pitch and delay interval, with the ability to alter any parameters in real-time using the Ribbon controller.
- Four independent voices (labeled as A, B, C, D) with diatonic pitch shifting and delay
- Select Key and Scale to create harmonies that coincide with your compositions or use the Learn button to set the key by the incoming note you play
- Group the four delays so that they are evenly spaced or spread out
- Sync the delays to tempo, or a value of your own choosing
- The Ribbon controller allows for dynamic modification of several knobs at once to easily morph between settings
- Factory presets help get you started or create your own User presets
- Mixlock helps when auditioning different presets by enabling a global Mix value that will remain constant for every subsequently loaded preset
- Works as a standalone app, AudioUnit v3 effect, or Inter-App Audio effect
Embedded here is the official overview from Eventide Audio.