Comparison

24 vs Scouter Synth

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

Head to head
About

24

Explore microtonal music with a virtual keyboard that plays notes between standard semitones. Hear quarter tones instantly, send them as MIDI to your DAW, and discover unique keyboard layouts that morph into each other.

Highlights
  • Microtonal keyboard for quarter tones
  • MIDI output to DAWs
  • Morphing keyboard layouts
  • Polyphonic and mono MIDI modes
  • Visual representation of 24-TET
  • On-device sound playback
Features
Read full description

Quarter tones on a keyboard you already know. 24-TET Keys is a microtonal keyboard for iPhone and iPad: play the notes between the notes with your fingers, hear them as you press them, and send them on as MIDI if you have somewhere to send them. CAN YOU PLAY QUARTER TONES ON A PIANO? Not on an ordinary one, which is why quarter-tone pianos are rare instruments in a handful of cities. Here the piano board is the starting point. Naturals sit in a row, sharps ride above them, and the quarter tones grow into the gaps with an animated morph, so you can watch 24-TET come out of the notes you already play. Charles Ives wrote his Three Quarter-Tone Pieces for two pianos tuned a quarter tone apart. WHAT DOES A QUARTER TONE SOUND LIKE? Press one. It makes sound out of the box, so you hear the interval instead of reading about it: polyphonic, played by touch, with glissando slides straight across the quarter tones. A quarter tone is half a semitone, 50 cents, the gap between two piano keys cut in two. MICROTONAL CHORDS, NOT JUST SCALES Every finger is its own voice, so a neutral third holds its pitch inside a chord instead of dragging the other notes with it. That is the part quarter tones usually break. LAYOUTS THAT MORPH INTO EACH OTHER This is an experimental collection of unusual keyboard layouts, and not a menu of separate boards: each is a point in one space, and any of them morphs into any other while you watch. The piano-derived board is one point. So is a domino board, where a key carries its natural below and its quarter tone above. So is a snake through the honeycomb. So is an isomorphic layout, where a chord shape is the same shape in every key, the property that makes hex boards worth learning. You can morph out of the piano you know straight into the honeycomb, the bridge between the two. MICROTONAL MIDI KEYBOARD: SEND IT TO A DAW If you already make music and want quarter tones in it, this is the compact microtonal MIDI keyboard part. It sends over a virtual CoreMIDI source to GarageBand, Logic, AUM and other hosts, over USB, network MIDI or MIDI hardware. In poly mode each held note takes its own channel, so a quarter-tone chord arrives in tune; mono mode suits a single-channel instrument. Quarter tones travel as a pitch bend on the in-between notes. WHAT IS 24-TET? 24-TET, also written 24 tone equal temperament and closely related to 24 EDO, cuts the octave into 24 equal steps instead of 12. Each step is a quarter tone. It is the tuning behind much modern microtonal and xenharmonic writing, and the usual way Western notation approximates Middle Eastern maqam. It is an equal temperament, not a Just Intonation system. FAQ How do quarter tones work? They divide the semitone in half. 12-TET gives 12 equal steps per octave; 24-TET gives 24, so a new note lands exactly between every pair you already know. Which instruments can play quarter tones? Voices, fretless strings and many winds can bend to them; fixed-pitch keyboards usually cannot, which is what this app changes. Why don't we use quarter tones? Mostly because the instruments cannot play them. An ordinary piano has 12 keys per octave and no room for more. That is the limit this app removes. How do I make microtonal music with it? Play it as it is, or route the MIDI into your DAW and record the quarter tones onto a track like any other part. Can MIDI be microtonal? Yes. Each quarter tone travels as a pitch bend on the in-between notes, one voice per channel, so a chord stays in tune. Does it import Scala or .scl files? No. It plays 12-TET and 24-TET. Is it a tuner? No. It is a keyboard you play. No ads, no account. Want a standalone instrument to just play? Try our companion app Fingerophone.

About

Scouter Synth

Create music with a retro handheld console interface. Compose melodies, add synth sounds or samples, and mix tracks with effects. Perform live with a touch-sensitive pad and punch-in effects.

Highlights
  • Eight-track music composition
  • Multiple synth voices and sample playback
  • On-board effects and mixing console
  • Performance pad for live parameter control
  • MIDI and Bluetooth controller support
  • Import and record audio samples
Features
Read full description

ScouterSynth is a music tracker built like a handheld console. Eight tracks, a D-pad, two buttons, and no menus — every operation is a chord you can play with your thumbs. WRITE Phrases of sixteen rows, chains of phrases, and a song made of chains. Write a bassline once and place it four times with different transposes; change it later and every one of those places changes with it. Phrases can be shorter than sixteen rows, so six-eight is as easy as four-four. SOUND A synth voice per track — saw, pulse with PWM, triangle and sine, through a resonant filter and an envelope — or a sample, played whole or sliced. Wavetables for the sounds a plain oscillator cannot make. Per-tick tables for automation that runs faster than a row. SAMPLE Import from anywhere on your phone, or record straight into a slot from the microphone. MP3, AAC, M4A, AIFF and WAV are all converted on the way in. Whatever you choose is copied into your project, so a saved song carries its audio with it. MIX Ten lanes on one screen — eight tracks and two send buses — with level, pan, mute and solo, and three effect slots on each: filter, bitcrush and a tempo-synced delay. Watch the desk as a set of numbers or as ten live traces. PLAY A performance pad wires any two parameters to an X and a Y axis and moves every track at once. A grid of twelve pads holds six punch-in effects — an octave down, tape slow, a stutter, a bitcrush, a high pass and a low pass — held rather than latched, so nothing can be left on by accident, and six one-shot samples to fire over the top. SEE A radar sweep that reads the mix by frequency, a scope on the output, and six palettes to put it all in. INTEGRATE MIDI in and out with clock. A Bluetooth game controller, mapped button by button to whatever pad you own. Export the whole arrangement to a WAV. Songs, samples and exports all sit in the Files app where you can reach them. No accounts. No subscriptions. No network. The manual is inside the app — press SELECT and B on any screen.

Screenshots

243 screens
Scouter Synth4 screens

Verdict

The call

The clearest difference is update cadence: 24 at daily against Scouter Synth's every 4 weeks. 24 also leads on ratings volume (5 vs 1). Scouter Synth's advantage is rating (5.0 vs 4.6). On price, ads, in-app purchases and monetization model 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. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Scouter Synth holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: 24 has 5 ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

24 ships an update daily, Scouter Synth every 4 weeks. Both last shipped on October 24, 2026.

Scorecard3 real differences · 7 level
24 versus Scouter Synth: the parameters behind the verdict, then further details
Parameter24Scouter Synth
PriceFreeFree
Rating4.6 (5 ratings)5.0 (1 ratings) — better
Positive reviews100.0% of reviews—
Number of ratings5 — better1
Update frequencyDaily — betterEvery 4 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPadiPhone, iPad
Requires iOS17.617.0 — better
Further details — not scored
Size14 MB7 MB
Age rating4+4+
DeveloperMaxim OranskyAndrew Scott

Customer experience

24

All ratings5 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews3 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Scouter Synth

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

24

No in-app purchases

None

Scouter Synth

No in-app purchases

Questions

Is 24 free?
24 is free to download, with no in-app purchases.
Is Scouter Synth free?
Scouter Synth is free to download, with no in-app purchases.
Which has better reviews, 24 or Scouter Synth?
Scouter Synth is rated higher. 24 averages 4.6 out of 5 from 5 ratings, while Scouter Synth averages 5.0 from 1 ratings.
Do 24 or Scouter Synth have ads?
Neither 24 nor Scouter Synth shows ads.
Which is updated more often, 24 or Scouter Synth?
24 ships an update daily, and Scouter Synth every 4 weeks. Most recently, 24 was updated on October 24, 2026 and Scouter Synth on October 24, 2026.

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