Comparison

ChordTrainer vs Scale Runner

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

Head to head
About

ChordTrainer

Features
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Chord Trainer helps musicians practice chord spelling and ear training on a touch piano — anytime, in any key. Features: - Recognition mode: read a chord name and play it on the keyboard - Ear training: listen and reproduce the chord - Roman numerals: practice I–IV–V and more for key-to-degree fluency - Mistake Book / Retry misses — only the chords you got wrong - Lookup: type a chord symbol and see it light up on the piano - Free difficulties for Identify & Train; session and recent stats - Optional Chord Trainer Pro ($6.99/month, 7-day free trial): Sevenths, Extended, Mix, chord progressions, and full stats - Optional Support purchases in Settings ($0.99 and $4.99). They unlock no features - Works offline with no account required Practice chords anytime. Get familiar with every chord, master key-to-degree fluency, and train your ear. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Scale Runner

Features
Read full description

Scale Runner turns music theory into something you play, not something you read. Pick a mode and the app names a scale or a chord. You answer on a MIDI keyboard or the on-screen keys, and every note is checked as you play it. In the timed modes it checks when you played, too, against a metronome that never drifts. SIX WAYS TO PRACTICE • Scales: play scales from a random key, note by note • Chords: build the named chord, holding all the notes at once • Voicings: capture a shape you like, then play it in all 12 keys • Scale Running: hold chords and run their modes in time, key by key • Inversion Running: walk a chord up its inversions an octave and back down • Jam Mode: comp diatonic chords in time, one per bar, in a single key VOICINGS: YOUR SHAPES, IN EVERY KEY Play a voicing you want to own, say a drop 2, a rootless 13th or a stack of fourths. Tap its root and Scale Runner spells the shape out in degrees from the bass up. Name it, then drill it around all 12 keys. It is judged by shape rather than exact pitches, so you can play it wherever it falls under your hands, in any octave. Keep a library in order with folders, colour tags, text tags, search and drag-to-reorder. Three saved voicings free, unlimited with Pro. INVERSION RUNNING: ONE CHORD, TOP TO BOTTOM Walk a chord up through every inversion to the octave and back down, so your hand moves through the positions instead of jumping between them. The keyboard transposes to each new root, so the shape stays where you can see it. Run it untimed to build the map, or start the metronome and be judged a position per beat. JAM MODE: COMPING IN TIME Stay in one key and comp its diatonic chords against the click, one per bar. Follow the changes the app calls, or switch to freestyle and pick your own way through the key while it scores what you land on. Loosen it with "any chord tones", which accepts any voicing of three or more notes with the root in the bass, so the way you actually comp counts, not just textbook triads. Sessions run for as many bars as you set, after a counted-in start. SCALE RUNNING: CHORDS AND MODES AT ONCE Hold the diatonic chord in one hand and run its mode in the other, one note per beat, bar after bar, through a progression and around the keys. Set the progression, triads or sevenths, passes per key, and whether keys move chromatically or by fifths. WHAT'S COVERED • 25 scales: all 21 modes of the major, harmonic minor and melodic minor scales, plus both pentatonics, blues and chromatic • 13 chord types: triads, sixths, sevenths, sus and diminished • All 12 keys, cycled chromatically or by fifths • 5 progression presets, including 12-bar blues, as triads or sevenths PLAY IT YOUR WAY Connect any class-compliant MIDI keyboard over USB or Bluetooth and the app remembers it, reconnecting on its own next time. No keyboard? The on-screen keys do everything. TIMING YOU CAN TRUST The metronome runs on absolute time, so it stays honest from 40 to 240 BPM. A quick calibration measures your audio and Bluetooth latency and subtracts it, so an on-beat press reads as on-beat. Set the windows to Easy, Normal or Strict. KEEP THE HABIT Daily streaks with milestones, reminders at a time you choose, and per-key, per-chord and per-mode stats that show what you have actually drilled. PRACTICE WITH FRIENDS (OPTIONAL) Sign in to back up your streak, invite friends, applaud their practice and compare streaks. Only your display name, avatar and streak are shared, and only with friends you invite. Everything else works signed out and offline. SCALE RUNNER PRO A one-time unlock, yours forever on all your devices: • Scale Running, Inversion Running and Jam Mode, unlimited • Full progression presets, sevenths and key cycles • Unlimited saved voicings • Streak protection: one missed day a week is repaired automatically Every timed mode is free to try three times before you decide.

Screenshots

ChordTrainer4 screens
Scale Runner4 screens

Verdict

The call

ChordTrainer and Scale Runner 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.

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. ChordTrainer sells 3 one-off in-app purchases and Scale Runner sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 9 days. The most recent releases landed on October 31, 2026 and November 6, 2026 respectively.

ScorecardNo meaningful differences
ChordTrainer versus Scale Runner: the parameters behind the verdict, then further details
ParameterChordTrainerScale Runner
PriceFreeFree
Update frequencyEvery 9 daysEvery 9 days
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPad, iPodiPhone, iPad, iPod, Mac — better
Requires iOS15.015.0
Further details — not scored
Size11 MB36 MB
Age rating4+4+
DeveloperSio Long ChanC1GNUS STUD1O

In-app purchases

3 purchases

ChordTrainer

One-time3
  • Support (Small)$0.99
  • Support (Large)$4.99
  • Chord Trainer Pro$9.99
1 purchases

Scale Runner

One-time1
  • Scale Runner Pro$14.99

Questions

Is ChordTrainer free?
ChordTrainer is free to download, with in-app purchases available.
Is Scale Runner free?
Scale Runner is free to download, with in-app purchases available.
Do ChordTrainer or Scale Runner have ads?
Neither ChordTrainer nor Scale Runner shows ads.
Which is updated more often, ChordTrainer or Scale Runner?
ChordTrainer ships an update every 9 days, and Scale Runner every 9 days. Most recently, ChordTrainer was updated on October 31, 2026 and Scale Runner on November 6, 2026.

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