# MARRS vs ChordProg Ear Trainer

The clearest difference is review sentiment: ChordProg Ear Trainer at 75% against MARRS's 0%. ChordProg Ear Trainer also leads on update cadence (every 5 days vs every 14 months). MARRS's advantage is in-app purchases (none vs 3) and iOS requirement (12.0 vs 14.0). On price, ads and device support there is nothing between them.

Both are free to download. ChordProg Ear Trainer sells 3 in-app purchases, starting at $2.99 per month. MARRS asks for nothing beyond the download.

MARRS ships an update every 14 months, ChordProg Ear Trainer every 5 days. Both last shipped on October 24, 2026.

## The numbers

| Metric | MARRS | ChordProg Ear Trainer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.4 (16 ratings)](https://appshunter.io/ios/app/chordprog-ear-trainer/id1454739512/reviews)** |
| Number of ratings | — | **16** |
| Positive reviews | 0.0% of reviews | **75.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 14 months | **Every 5 days** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 43 MB | 116 MB |
| Requires iOS | **12.0** | 14.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [THE UNIVERSITY OF HUDDERSFIELD ENTERPRISES LIMITED](https://appshunter.io/developer/1023669920) | [DevDa AS](https://appshunter.io/developer/1708225323) |

## What reviewers say

### MARRS

[App page](https://appshunter.io/ios/app/marrs/id1295926126)

This application simulates microphone arrays for sound localization prediction. It offers an object-based workflow to configure microphone setups and predict perceived sound source positions based on psychoacoustic models. The tool also automatically configures arrays for desired spatial scenes, considering microphone height and vertical orientation.

**Highlights:** Interactive object-based workflow, Graphical user interface, Localization prediction, Microphone array configuration, Psychoacoustic modeling, Automatic array setup, Considers microphone height and orientation

**Features:** macOS Compatibility

**In-app purchases:** none


### ChordProg Ear Trainer

[App page](https://appshunter.io/ios/app/chordprog-ear-trainer/id1454739512)

This app offers a realistic music training experience by using real audio clips to teach chord progressions, intervals, chords, and scales. It provides over 500 audio clips for practice and is designed to help prepare users for ear training tests.

**Highlights:** Chord progression recognition, Interval recognition exercises, Chord recognition exercises, Scale recognition exercises, 500+ real audio clips, Music theory exploration, Regular updates with new features

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly premium subscription! | $2.99 | per month |
| Yearly Premium Subscription! | $24.99 | per year |
| Premium Access | $9.99 | one-time |


## Frequently asked questions

### Is MARRS free?

MARRS is free to download, with no in-app purchases.

### Is ChordProg Ear Trainer free?

ChordProg Ear Trainer is free to download, with in-app purchases available.

### Do MARRS or ChordProg Ear Trainer have ads?

Neither MARRS nor ChordProg Ear Trainer shows ads.

### Which is updated more often, MARRS or ChordProg Ear Trainer?

MARRS ships an update every 14 months, and ChordProg Ear Trainer every 5 days. Most recently, MARRS was updated on October 24, 2026 and ChordProg Ear Trainer on October 24, 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.*