Comparison

Isotope MIDI Keyboard vs polymachine

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

Head to head
About

Isotope MIDI Keyboard

This app offers an intuitive and accessible way to play music and learn music theory. Its unique isomorphic grid layout simplifies chord playing and understanding note relationships, making it ideal for both beginners and experienced musicians.

Highlights
  • Isomorphic grid layout for intuitive playing
  • Built-in Element sound engine
  • Audio Unit v3 plugin support
  • MIDI and MIDI over Bluetooth connectivity
  • Velocity-based touch and accelerometer input
  • Customizable themes and layouts
Features
Read full description

Isotope is an isomorphic MIDI keyboard app for iOS. Isotope makes playing music fun and intuitive, while also making music theory more accessible. Unlike traditional keyboard, Isotope's isomorphic grid layout is based on mathematical and geometrical properties of sound itself. When you play it, it's much more intuitive. When you want to learn about music, it shows how notes relate to one another. # Isomorphic Keyboard - If the interval stays the same, the form of your hand stays the same. For instance, when you put your first finger on the C, third finger on the E and the second finger on the G, it's the C major chord. Now that your fingers are in a triangle, if you just go up by one row, now it becomes the F major chord. - Square-based isomorphic keyboards like Isotope resembles stringed instruments tuned in perfect 4th apart from one string to the next. Therefore, if you have an experience in playing stringed instruments like the guitar, the bass, the violin, or the cello, you will get learn to play Isotope quickly. # Element - Built-in Sound Engine for Isotope - Available as an Audio Unit v3 plugin - Element has a versatile sound characteristics resembles double bass and bass guitars in the lower range, electric piano in the mid range and woodwind in the higher frequency range. # Connectivity - Supports MIDI (Garageband, Drambo, FL Studio Mobile etcs.) - MIDI over Bluetooth (For connecting Isotope to your computers / or any other devices that support MIDI over Bluetooth) # Usability - Multi-window and Slide Over support on iPadOS - Velocity based on touch area and accelerometer - 3rd party Audio Unit instrument plugins # Customizability - Row Interval adjustment - Fully customizable themes - Resizable buttons / app windows

About

polymachine

This app offers a unique approach to music creation by combining geometric principles with modular synthesis. Explore generative algorithmic drums, oscillators, and harmonies, with specialized tools for 808s and kick drum integration.

Highlights
  • Geometric music theory integration
  • Modular synthesis engine
  • Generative algorithmic drums
  • Oscillators and harmonies
  • 808 and kick drum linking
  • Log drum pattern generator
Features
Read full description

Geometry of Music + Modular Synthesis Powerhouse, Generative Algorithmic Drums + Oscillators and Harmonies. FL Soft Clip and FL Distortion on 808s. 808s tied to Kicks. Log Drum Pattern generator

Screenshots

Isotope MIDI Keyboard4 screens
polymachine4 screens

Verdict

The call

The clearest difference is price: polymachine at Free against Isotope MIDI Keyboard's $6.99. polymachine also leads on review sentiment (100% vs 80%). Isotope MIDI Keyboard's advantage is rating (4.9 vs 2.5) and update cadence (every 2 days vs weekly). On ads, in-app purchases, monetization model and device support 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

polymachine is free to download; Isotope MIDI Keyboard costs $6.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Isotope MIDI Keyboard holds the better App Store score, 4.9 against 2.5. That said, the two scores are not equally well evidenced: Isotope MIDI Keyboard has 10 ratings behind it against 2, so its average is the more settled of the two. Written reviews complicate that: 80% of Isotope MIDI Keyboard's written reviews are positive against 100% of polymachine's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Isotope MIDI Keyboard ships an update every 2 days, polymachine weekly. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

Scorecard5 real differences · 5 level
Isotope MIDI Keyboard versus polymachine: the parameters behind the verdict, then further details
ParameterIsotope MIDI Keyboardpolymachine
Price$6.99Free — better
Rating4.9 (10 ratings) — better2.5 (2 ratings)
Positive reviews80.0% of reviews100.0% of reviews — better
Number of ratings10 — better2
Update frequencyEvery 2 days — betterWeekly
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.015.0 — better
Further details — not scored
Size3 MB93 MB
Age rating4+4+
DeveloperJaewon ChoiMike Gao

Customer experience

Isotope MIDI Keyboard

All ratings10 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews10 reviews
Positive80.0%
Neutral10.0%
Negative10.0%

polymachine

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Isotope MIDI Keyboard

No in-app purchases

None

polymachine

No in-app purchases

Questions

Is Isotope MIDI Keyboard free?
Isotope MIDI Keyboard costs $6.99, with no in-app purchases.
Is polymachine free?
polymachine is free to download, with no in-app purchases.
Which has better reviews, Isotope MIDI Keyboard or polymachine?
Isotope MIDI Keyboard is rated higher. Isotope MIDI Keyboard averages 4.9 out of 5 from 10 ratings, while polymachine averages 2.5 from 2 ratings.
Do Isotope MIDI Keyboard or polymachine have ads?
Neither Isotope MIDI Keyboard nor polymachine shows ads.
Which is updated more often, Isotope MIDI Keyboard or polymachine?
Isotope MIDI Keyboard ships an update every 2 days, and polymachine weekly. Most recently, Isotope MIDI Keyboard was updated on October 24, 2026 and polymachine on October 25, 2026.

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