# Clustering vs Keys Trainer

The clearest difference is price: Keys Trainer at $2.99 against Clustering's $5.99. Keys Trainer also leads on iOS requirement (12.0 vs 15.6). On review sentiment, update cadence, ads and in-app purchases there is nothing between them.

Clustering costs $5.99 and Keys Trainer $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Clustering ships an update every 5 months, Keys Trainer every 9 months. The most recent releases landed on June 1, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | Clustering | Keys Trainer |
| --- | --- | --- |
| Price | $5.99 | **$2.99** |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/keys-trainer/id1525979034/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | 0.0% of reviews | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 5 months** | Every 9 months |
| Monetization | Paid | Paid |
| Size | 60 MB | 30 MB |
| Requires iOS | 15.6 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [tingjing.com](https://appshunter.io/developer/442007900) | [Plearn LLC](https://appshunter.io/developer/6792172523) |

## What reviewers say

### Clustering

[App page](https://appshunter.io/ios/app/clustering/id1469460016)

This music practice tool allows improvisers to set up chordal structures and use them as practice material. Explore root movements through various cycles to discover new musical ideas and enhance your practice routine.

**Highlights:** Set up chordal structures, Use clusters for practice, Explore root movements, Practice through cycles (fourths, chromatic), Enhance musical practice

**Features:** macOS Compatibility

**In-app purchases:** none


### Keys Trainer

[App page](https://appshunter.io/ios/app/keys-trainer/id1525979034)

Master key signatures and scales with this music learning app. Practice identifying keys, understanding note sharps/flats, and instantly recognizing scale layouts on a keyboard. Features include customizable practice, passive viewing, and a challenging game mode.

**Highlights:** Key signature recognition, Scale layout identification, Customizable learning range, Intelligent training based on performance, Practice, View, Game, and Search modes, Earn coins, medals, and trophies

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Clustering free?

Clustering costs $5.99, with no in-app purchases.

### Is Keys Trainer free?

Keys Trainer costs $2.99, with no in-app purchases.

### Do Clustering or Keys Trainer have ads?

Neither Clustering nor Keys Trainer shows ads.

### Which is updated more often, Clustering or Keys Trainer?

Clustering ships an update every 5 months, and Keys Trainer every 9 months. Most recently, Clustering was updated on June 1, 2026 and Keys Trainer on October 5, 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.*