# MultiTracks.com ChartBuilder vs Number System Trainer

The clearest difference is review sentiment: Number System Trainer at 100% against MultiTracks.com ChartBuilder's 63%. Number System Trainer also leads on in-app purchases (none vs 4) and update cadence (weekly vs monthly). MultiTracks.com ChartBuilder's advantage is ratings volume (6K vs 10) and chart position (#101 vs unranked). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. MultiTracks.com ChartBuilder sells 4 in-app purchases, starting at $2.99 per month. Number System Trainer asks for nothing beyond the download.

Number System Trainer holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: MultiTracks.com ChartBuilder has 6K ratings behind it against 10, so its average is the more settled of the two. Written reviews point the same way: 63% of MultiTracks.com ChartBuilder's written reviews are positive against 100% of Number System Trainer's.

MultiTracks.com ChartBuilder ships an update monthly, Number System Trainer weekly. The most recent releases landed on September 30, 2026 and September 14, 2026 respectively.

## The numbers

| Metric | MultiTracks.com ChartBuilder | Number System Trainer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (6K ratings)](https://appshunter.io/ios/app/multitrackscom-chartbuilder/id1208264687/reviews) | **[5.0 (10 ratings)](https://appshunter.io/ios/app/number-system-trainer/id6786437503/reviews)** |
| Number of ratings | **6K** | 10 |
| Positive reviews | 62.8% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Monthly | **Weekly** |
| Monetization | Subscription | **Free with in-app purchases** |
| Best chart rank | **#101** | — |
| Size | 283 MB | 10 MB |
| Requires iOS | 15.4 | **15.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [MultiTracks.com](https://appshunter.io/developer/751755887) | [Brandon Oaks](https://appshunter.io/developer/6786437505) |

## What reviewers say

### MultiTracks.com ChartBuilder

[App page](https://appshunter.io/ios/app/multitrackscom-chartbuilder/id1208264687)

**Currently charting:** #101 Top Grossing · Music (US App Store)

Customize song charts with adjustable keys, capo settings, and chord displays. Add annotations, create setlists, and sync with audio playback for seamless practice and performance. Access a vast library of charts with a subscription.

**Highlights:** Endless chart customization, Adjustable key, capo, and chord display, In-app annotations and highlighting, Setlist creation and collaboration, Sync with audio playback, Multiple chart type options

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| ChartBuilder App | $2.99 | per month |
| Solo Practice Bundle | $6.99 | per month |
| Content Subscription | $14.99 | per month |
| Chart Pro | $21.49 | per month |

**What reviewers like**

- 🚀 Great resource for worship teams
- 👍 Helpful for practice and live performances
- 🔒 Protects intellectual property
- 🔧 Customizable chord charts and setlists
- 🎨 Clean and intuitive user interface

**What reviewers complain about**

- 🐛 Buggy and unstable at times
- 🔑 Subscription issues and login problems
- 🔇 Audio playback and syncing issues
- 🚫 Lacks some basic features like annotation
- 💰 Expensive for the issues experienced

**Reported bugs**

- Crashes and freezes on launch
- Inconsistent key changes and song resets
- Sync issues between devices and the web portal
- Screenshots triggering account disabling warnings
- Inability to use app while locked or in background

**Requested features**

- Ability to customize arrangements and parts
- Improved offline functionality
- More control over click track and vocal cues
- Better integration with other apps and devices
- Increased font size and accessibility options


### Number System Trainer

[App page](https://appshunter.io/ios/app/number-system-trainer/id6786437503)

Learn and master the Nashville Number System for music. This app offers interactive modules to help musicians of all levels understand chord progressions, transpose songs, and improve their ear training. It's designed for quick learning and on-the-fly musical communication.

**Highlights:** Interactive learning modules, Chord reading and identification, Instant transposition, Ear training exercises, Visual chord shapes, Circle of 4ths & 5ths reference

**Features:** macOS Compatibility, Family Sharing

**In-app purchases:** none


## Frequently asked questions

### Is MultiTracks.com ChartBuilder free?

MultiTracks.com ChartBuilder is free to download, with in-app purchases available.

### Is Number System Trainer free?

Number System Trainer is free to download, with no in-app purchases.

### Which has better reviews, MultiTracks.com ChartBuilder or Number System Trainer?

Number System Trainer is rated higher. MultiTracks.com ChartBuilder averages 4.8 out of 5 from 6K ratings, while Number System Trainer averages 5.0 from 10 ratings.

### Do MultiTracks.com ChartBuilder or Number System Trainer have ads?

Neither MultiTracks.com ChartBuilder nor Number System Trainer shows ads.

### Which is updated more often, MultiTracks.com ChartBuilder or Number System Trainer?

MultiTracks.com ChartBuilder ships an update monthly, and Number System Trainer weekly. Most recently, MultiTracks.com ChartBuilder was updated on September 30, 2026 and Number System Trainer on September 14, 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.*