# 丸単 vs Trombone Trainer

丸単 and Trombone Trainer are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

Both are free to download. 丸単 sells 10 one-off in-app purchases and Trombone Trainer sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

丸単 ships an update every 4 days, Trombone Trainer every 5 days. The most recent releases landed on October 24, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | 丸単 | Trombone Trainer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/trombone-trainer/id6788198664/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 4 days** | Every 5 days |
| Monetization | — | Free with in-app purchases |
| Size | 7 MB | 106 MB |
| Requires iOS | **17.0** | 18.0 |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [sungjae park](https://appshunter.io/developer/1896477219) | [Edmund Trujillo](https://appshunter.io/developer/1862926811) |

## What reviewers say

### 丸単

[App page](https://appshunter.io/ios/app/id6767459920)

**Features:** Family Sharing

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| TOPIK Upgrade 3 | $0.49 | one-time |
| TOPIK Upgrade 4 | $0.49 | one-time |
| All Upgrade Mixed | $0.49 | one-time |
| All Upgrade 4 TOPIK | $0.99 | one-time |
| TOPIK Upgrade 2 | $1.99 | one-time |
| All Upgrade 3 TOPIK | $1.99 | one-time |
| All Upgrade TOPIK | $1.99 | one-time |
| All Upgrade HANKEN | $1.99 | one-time |
| All Upgrade 2 TOPIK | $3.99 | one-time |
| All Upgrade 1 TOPIK | $4.99 | one-time |


### Trombone Trainer

[App page](https://appshunter.io/ios/app/trombone-trainer/id6788198664)

This app helps brass players improve their trombone slide technique through interactive exercises and real-time scoring. It offers a slide position chart, ear transcription, and built-in practice libraries. Track your progress with detailed statistics and unlockable badges.

**Highlights:** Interactive slide position chart, Real-time scoring and clean-run detector, Transcribe music by ear onto staff, Bass-clef staff notation, Play-along loops with chords, Progress tracking and unlockable badges, Multiple note name display options

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Standard — All Songs | $19.99 | one-time |
| Pro — Author & Export | $39.99 | one-time |


## Frequently asked questions

### Is 丸単 free?

丸単 is free to download, with in-app purchases available.

### Is Trombone Trainer free?

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

### Do 丸単 or Trombone Trainer have ads?

Neither 丸単 nor Trombone Trainer shows ads.

### Which is updated more often, 丸単 or Trombone Trainer?

丸単 ships an update every 4 days, and Trombone Trainer every 5 days. Most recently, 丸単 was updated on October 24, 2026 and Trombone Trainer on October 19, 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.*