# Harmonizr — smart musical harmonizer

> Vocal harmonizer app for creating automatic harmonies with MIDI or on-screen input. (iPhone/iPad app by Matthew Robbins.)

- Source: https://appshunter.io/ios/app/harmonizr/id1348742174 (this page in markdown: same URL + `.md`)
- Developer: [Matthew Robbins](https://appshunter.io/developer/1348742173)
- Category: Music, Entertainment
- Price: $4.99
- Rating: 4.20/5 from 27 App Store ratings · 23 written reviews indexed
- Age rating: 4+
- Requires: iOS 18.6 · 5 MB
- Languages: American English
- Released: 2018-05-31
- Data updated: 2026-08-31
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/harmonizr/id1348742174/reviews.md

## What is Harmonizr?

Harmonizr is a vocal harmonizer offering a unique and fun user interface.  Plug in a pair of headphones and sing a melody, tapping the correct key center buttons, and Harmonizr will follow, synthesizing up to three voices of automatic harmony in your own voice.  Plug in a MIDI keyboard, or use the on-screen one, and you can sing harmony like Imogen Heap or Jacob Collier, matching every note you play.  Harmonizr also can also be used as an Audio Unit (AUV3) extension within other apps, such as GarageBand, AUM, or Cubasis, and can be controlled by MIDI controller apps like SoundPrism.

## Key features

- Automatic vocal harmony synthesis
- Real-time key center selection
- MIDI keyboard integration
- On-screen MIDI keyboard
- Audio Unit (AUV3) extension support
- Control via MIDI controller apps

## Chart rankings

- #112 in Top Paid · Music (US App Store)

## Recent user reviews (10 of 23)

All indexed reviews: https://appshunter.io/ios/app/harmonizr/id1348742174/reviews.md

### 1/5 — Do you stillSupport this app?

*2023-02-26, version 1.7*

Hi - I bought this and I wonder if the reason it doesn’t work is that you haven’t updated it to work with Apples iOS systems. Please let me know as I do not get the menu screens you show online.

### 5/5 — BACK on the App Store!!!

*2022-08-25, version 1.7*

Harmonizr was unavailable for a little while, but the great Developer has reopened it back on the App Store. Buy it while you can it is THE best vocal processing harmony app available. Cheers and thank you to Matthew Robbins!

### 5/5 — Excellent!

*2021-12-01, version 1.7*

Really impressed with this. Very versatile, yet straightforward to use. Really good midi implementation.

### 3/5 — Can’t hear keyboard output

*2021-06-16, version 1.7*

It seems like a really cool and useful app for what I’d like to do.  The keyboard, however, doesn’t produce sound.  What you see are lights blinking on the keys which are, I’m guessing, related to the key you’re in.  Beyond that, I can’t hear anything.  Would love to try out the whole app soon.  Thank you.

### 5/5 — So much fun for vocals and fake trumpet

*2021-01-24, version 1.7*

I have looked for something like this for a while on the computer and never thought to check the App Store. I love the functionality and simplicity of this app.

### 5/5 — Great little app

*2021-01-01, version 1.7*

For me the best feature is the ability to customize the presets so it operates like a rotator, using either midi or audio.
Works great with iRig 2 audio interface or iRig midi interface.
Nicely done, developer!

### 5/5 — a solid little harmonizer!

*2020-09-14, version 1.7*

Super easy to use out of the box (the tutorial when you first open the app is super helpful). I confirmed that it works with a USB midi input, and the ability to choose which mic to use is handy when you have cheap earphones with a low quality built-in mic. Thanks for making this!

### 5/5 — I've been looking for an app like this for years! :D

*2020-08-27, version 1.7*

Thank you so much. I couldn't be more excited. It's so much fun and I wish I'd found this app years sooner. I'd really like to be able to use this live and I'll be investigating ways to do that.

Update: The developer is super responsive to feedback and I’m thrilled with the continual updates!

### 5/5 — Midi doesn’t work

*2020-08-08, version 1.7*

I rarely write reviews but I got excited for this app. Only to find that it doesn’t work at all. When accessing bluetooth midi there’s no option to go back and try it for yourself. Also plugging in a midi controller by way of iRig pro, it still doesn’t work.

Edit: It was a user error, when I first used this app, it did have a weird problem where you couldn’t hit the back button, that problem is now fixed. My user error was my keyboard was for some reason sending things to a different midi channel and the app was not registering the notes. I have an M-Audio Keystation 88, all I had to do was press the advance button and change the midi channel to 1 and the app works great now. Best harmonizer app out there thanks for being a nerd and keep going strong.

### 5/5 — Gorgeous

*2019-12-22*

Brilliant app that offers huge amounts of possibilities. Such a beautiful music tool! 

My only suggestion for improvement is the ability to create your own presets. 

Other than that it‘s simply great!

## Frequently asked questions about Harmonizr

### What is Harmonizr's price?

Harmonizr is a paid app, currently priced at $4.99. This one-time purchase grants you full access to all its features without additional costs.

### What devices does Harmonizr support?

Harmonizr is compatible with iPhone, iPad, and iPod. It is designed to work seamlessly across Apple's mobile and tablet ecosystem.

### How often is Harmonizr updated?

The latest version of Harmonizr is 1.7, released on August 4, 2020. While updates have not been frequent recently, the app is stable and functional.

### What is the age rating for Harmonizr?

Harmonizr has an age rating of 4+, making it suitable for users of all ages. It does not contain any mature content.

### Can Harmonizr be used with other music apps?

Yes, Harmonizr can be used as an Audio Unit (AUV3) extension within other music production apps like GarageBand, AUM, or Cubasis, allowing for integration into your existing workflow.

### What is the user sentiment for Harmonizr?

Harmonizr has a positive user reception, with an average rating of 4.2 stars from 26 ratings. Users appreciate its unique harmonizing capabilities.

### Does Harmonizr offer a free trial?

As Harmonizr is a paid application with a one-time purchase price of $4.99, it does not typically offer a free trial period. You can review its features and user ratings before purchasing.

### Can I control Harmonizr with external hardware?

Yes, Harmonizr can be controlled by MIDI keyboard input, both physical and on-screen. It also supports control by MIDI controller apps like SoundPrism.

## Version history (last 5 releases)

### 1.9 — 2026-05-14

Apologies, a compiler issue caused v 1.8 to not actually harmonize. Kind of the core functionality, and I didn't catch it before distributing. Thank you for your patience!

### 1.8 — 2026-05-14

UI compatibility changes, plus a noise gate, and re-designed modular DSP engine.

### 1.7 — 2020-08-04

* harmonizr should correctly load in more AUv3 host apps
* no more stuck voices in manual midi mode.

### 1.6 — 2020-07-19

* Built-in screen recording, with front-facing camera, so you can share your inspired moments with friends!
* Key center can be changed via MIDI CC messages, allowing automation in DAW programs such as Cubasis, or live performance with a pad controller!
* Hardware keyboard support for iPad, for no-look operation without a pad controller.
* Basic Looping: layer yourself!
* Improvements to the pitch detection algorithm - smoother harmonies with fewer glitches and dropouts when singing in noisy environments.

### 1.3 — 2019-02-05

* Fixed problem with MIDI button not turning off manual voices.
* Harmonizr now responds to MIDI program change messages, allowing it to follow your other MIDI gear from song to song on stage.
* Added new stereo modes: mono, and split, where the dry signal goes in channel one, and the harmony voices in channel 2.
* Cosmetic improvements to the interface.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-31.*