Comparison

MultiTracks.com ChartBuilder vs Number System Trainer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

MultiTracks.com ChartBuilder

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
Currently charting
Read full description

ChartBuilder® allows you to endlessly customize each chart to meet your needs. Change the Key, Capo, Chord Display, & Layout with filters. Write, type, & highlight in any song section on your charts with Annotations. Easily save & recall them at any time. Lead with confidence. ChartBuilder® Features: • Access to every chart in our catalog with an active ChartBuilder Content Subscription • Teams with RehearsalMix can listen to the original song with a specific instrument turned up or down! • Create & Collaborate on setlists with your team in Playback, ChartBuilder and on our Website. • Charts available in all 12 keys • ChartBuilder and RehearsalMix Sync: Your chart auto-scrolls as RehearsalMix audio plays • Loop individual song sections in the RehearsalMix • Chart Type options (Chords & Lyrics, Lyrics, or Song Map) • Chord Display options (Chords, Numbers, Numerals, or Do-Re-Mi) • Change song section style (Condensed or Full) • Annotations • Optional Song Map that matches the original recording and MultiTrack • Optional MD Notes • Browse songs by Title, Album, Genre, Theme, or Top Songs • Bluetooth Control (Compatible with AirTurn, Coda Music, Donner, and other external keyboard devices) • View user-generated Cloud Charts Solo Practice Bundle (5.99 per Month): • Free 30-day trial (Subscription renews at end of 30-day​ trial) • Payment will be charged to iTunes Account at confirmation of purchase. • Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period • The account will be charged for renewal within 24-hours prior to the end of the current period for $5.99 • Subscriptions may be managed by the user and auto-renewal maybe be turned off by going to the users' Account Settings after purchased • Any unused portion of a free trial period will be forfeited when the user purchases a subscription where applicable Terms of Use (https://www.multitracks.com/terms/) ChartBuilder Team Content (12.99 per Month): • Free 30-day trial (Subscription renews at end of 30-day​ trial) • Payment will be charged to iTunes Account at confirmation of purchase. • Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period • The account will be charged for renewal within 24-hours prior to the end of the current period for $12.99 • Subscriptions may be managed by the user and auto-renewal maybe be turned off by going to the users' Account Settings after purchased • Any unused portion of a free trial period will be forfeited when the user purchases a subscription where applicable • Terms of Use (https://www.multitracks.com/terms/) ChartBuilder App (1.99 per Month) • Free 30-day trial (Subscription renews at end of 30-day trial) • Payment will be charged to iTunes Account at confirmation of purchase. • Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period • The account will be charged for renewal within 24-hours prior to the end of the current period for $1.99 • Subscriptions may be managed by the user and auto-renewal maybe be turned off by going to the users' Account Settings after purchased • Any unused portion of a free trial period will be forfeited when the user purchases a subscription where applicable • Terms of Use (https://www.multitracks.com/terms/) Price may vary by location. Subscriptions will be charged to your credit card through your iTunes account. Your subscription will automatically renew unless canceled at least 24 hours before the end of the current period. You will not be able to cancel the subscription once activated. Any unused portion of a free trial will be forfeited if you upgrade from a free subscription to a paid version. Manage your subscriptions in Account Settings after purchase. For more details on our Privacy Policy and Terms of Use please visit: http://www.multitracks.com/privacy/ and http://www.multitracks.com/terms/

About

Number System Trainer

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
Read full description

Number System Trainer teaches you the Nashville Number System — the method worship musicians and session players use to learn songs fast, transpose on the fly, and communicate with any musician in any key. Whether you're a beginner who only knows 3 chords or an experienced worship leader, this app meets you where you are. 6 INTERACTIVE MODULES • Learn — A 5-step intro to how the number system works • Read Charts — 4 levels from basic chords to slash chords • Transpose — Move full progressions to any key instantly • Ear Training — 3 levels, identify chords just by listening • Play Along — See piano and guitar shapes in every key, with capo tips built in • Circle of 4ths & 5ths — Tap any key to see all 7 chords No login required. Works instantly.

Screenshots

MultiTracks.com ChartBuilder4 screens
Number System Trainer4 screens

Verdict

The call

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 (#102 vs unranked). On price, ads, device support and iOS requirement there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard7 real differences · 4 level
MultiTracks.com ChartBuilder versus Number System Trainer: the parameters behind the verdict, then further details
ParameterMultiTracks.com ChartBuilderNumber System Trainer
PriceFreeFree
Rating4.8 (6K ratings)5.0 (10 ratings) — better
Positive reviews62.8% of reviews100.0% of reviews — better
Number of ratings6K — better10
Update frequencyMonthlyWeekly — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationSubscriptionFree with in-app purchases — better
Best chart rank#102 — better—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.415.0 — better
Further details — not scored
Size283 MB10 MB
Age rating4+4+
DeveloperMultiTracks.comBrandon Oaks

Customer experience

MultiTracks.com ChartBuilder

All ratings6,021 ratings
Positive95.2%
Neutral2.0%
Negative2.8%
Written reviews269 reviews
Positive62.8%
Neutral10.4%
Negative26.8%

Number System Trainer

All ratings10 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews7 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

MultiTracks.com ChartBuilder

Reported bugs

5 issues
  • 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

5 requests
  • 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

Not enough reviews yet to summarise bugs or requests.

In-app purchases

4 purchases

MultiTracks.com ChartBuilder

Subscriptions4
  • ChartBuilder App$2.991 Month
  • Solo Practice Bundle$6.991 Month
  • Content Subscription$14.991 Month
Show 1 more
  • Chart Pro$21.491 Month
None

Number System Trainer

No in-app purchases

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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