Ryouta Kira, developer of KQ Dixie and KQ MiniSynth, released KQ Unotone. The app appears to be heavily inspired by Korg's Monotron, Monotron Duo, and Monotron Delay. You get 4 different AUv3 instruments and effects for just $2! The app also supports Audiobus, and Inter-app Audio.
KQ Unotone App Store Description:Just a Toy Synthesizer.
- Included: 2 Oscillators, LPF, Delay effector, Ribbon controller
- Not included: Envelope Generator
- The pitch changes when you tweak Delay Time.
- Also acts as a effector.
- Audio Unit is supported.
- Audiobus is supported.
- Inter-App Audio is supported.
You must use either "Instrument" or "Effector" when you connect it via Audiobus or Inter-App Audio.
Also Launching the app may be necessary on iOS 12.4 or later.
YouTuber Edward Gregory did a demo jam in the new app, exploring each of the "Toys" in the toybox.