# ChordInvert vs OnKey

The clearest difference is rating: ChordInvert at 5.0 against OnKey's 3.0. ChordInvert also leads on price ($1.99 vs $4.99). On ratings volume, update cadence, ads and in-app purchases there is nothing between them.

ChordInvert costs $1.99 and OnKey $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ChordInvert holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

ChordInvert ships an update every 6 weeks, OnKey every 2 months. The most recent releases landed on June 15, 2026 and September 7, 2026 respectively.

## The numbers

| Metric | ChordInvert | OnKey |
| --- | --- | --- |
| Price | **$1.99** | $4.99 |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/chordinvert/id1549606631/reviews)** | [3.0 (2 ratings)](https://appshunter.io/ios/app/onkey-scale-practice/id1638204692/reviews) |
| Number of ratings | 1 | **2** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 weeks** | Every 2 months |
| Monetization | Paid | Paid |
| Size | 9 MB | 2 MB |
| Requires iOS | **14.0** | 14.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Chris Crossen](https://appshunter.io/developer/1526216020) | [Rea Meir](https://appshunter.io/developer/1638204694) |

## What reviewers say

### ChordInvert

[App page](https://appshunter.io/ios/app/chordinvert/id1549606631)

This app visually teaches major and minor chord inversions. It displays notes on a staff, piano keys, and note names. A quiz feature helps build mastery and tracks progress.

**Highlights:** Graphical chord inversion reference, Major and minor chord inversions, Notes on musical staff, Highlighted piano keyboard, Note names with sharps/flats, Progress tracking quiz

**Features:** macOS Compatibility

**In-app purchases:** none


### OnKey

[App page](https://appshunter.io/ios/app/onkey-scale-practice/id1638204692)

This app generates readable, note-based exercises for practicing scales and chords. It's ideal for musicians of all levels looking for a focused and efficient way to improve their technique and theory knowledge without manual preparation.

**Highlights:** Generate note-based exercises, Select scale or chord type, Transpose to any key, Set range and clef, Choose from various patterns, Add note names and time signatures

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is ChordInvert free?

ChordInvert costs $1.99, with no in-app purchases.

### Is OnKey free?

OnKey costs $4.99, with no in-app purchases.

### Which has better reviews, ChordInvert or OnKey?

ChordInvert is rated higher. ChordInvert averages 5.0 out of 5 from 1 ratings, while OnKey averages 3.0 from 2 ratings.

### Do ChordInvert or OnKey have ads?

Neither ChordInvert nor OnKey shows ads.

### Which is updated more often, ChordInvert or OnKey?

ChordInvert ships an update every 6 weeks, and OnKey every 2 months. Most recently, ChordInvert was updated on June 15, 2026 and OnKey on September 7, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*