Comparison

Holon vs GSDSP MMM

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

Head to head
About

Holon

This app transforms your movement through cities into a dynamic, real-time musical score. It uses your physical location and activity to generate interactive synth music, encouraging outdoor exploration and turning listeners into performers.

Highlights
  • Human-powered music generation
  • Encourages outdoor activity
  • Zero UI for minimal distraction
  • Environmentally responsive music
  • Real-time synth music creation
  • Optional AirPods and Apple Watch integration
Features
Read full description

Holon makes the city your instrument. It turns your movement in the environment into a synthetic, interactive score that reflects your context, supports your activities and alerts you to changes in the surrounding area. Holon uses physical computing and a geospatial dataset to synthesize music on the iPhone in real time from your data - no streaming or AI involved, just pure DSP and logic. What Holon Does: * Human powered music. Every action generates dynamic, improvised synth music in real time. * Encourages outdoor activities. Holon doesn’t work in your apartment or by shaking your phone around. Move through streets, parks, and transit systems to make the music happen. * Stays out of your way. Zero UI means less screen time, no distractions. * Uses places and spaces to modify the music you make. The environment isn’t background - it’s the score. * The more and further you move, the more things happen in the music. Use your musical agency instead of skipping and swiping. Why Holon Exists:
 Music has been reduced to a commodity and a background activity for consumerism. Holon isn’t here to help you chill when you swipe, scroll and buy more stuff, or improve your focus when working for the Man. Holon is here to break away from the static, one-way relationship of streaming services and to put the human in the loop - yourself. Forget emoting celebrities with their false sincerity, throw overproduced passive soundscapes and statistical algorithms on the dung heap of history. Holon turns listeners into performers and unlocks the musical potential of places. How to Use: * Go outside - Holon needs space to function, just like you. Different districts, parks, bridges, shops, street furniture - all contribute to the musical output. Strolling around your apartment or shaking your phone won’t do. * Put the phone in your pocket or on your dashboard. * Walk, run, drive - the world is now the interface, space is the machine. * Use the big button in the middle to power Holon off when not in use - Auditory AR can be a battery-intensive process! * Optional Apple AirPods support for head-controlled musical interactions! * Optional Apple Watch support for heart rate-synced music (biofeedback) *the Watch app may take a moment to install* Requirements:
 * Available in over 1000 regions in more than 100 countries. * Check coverage or request a new area at holonic.systems/holon. * Best experienced with headphones. Ensure adequate battery level for extended use. * A data plan is required to access our geospatial engine but use of data is low. Holon: Become part of the circuit and… Become Sound™

About

GSDSP MMM

This app offers a robust MIDI modulation engine for controlling various instruments and plugins. It allows users to create dynamic audio with LFOs, random sources, and more, featuring a performance-focused interface for live use.

Highlights
  • MIDI CC control for plugins and hardware
  • LFOs, random sources, and envelope followers
  • Audio-based modulation capabilities
  • Dedicated Performance Skin for live use
  • AUv3 audio effect plugin
  • Desktop versions for Windows and macOS
Features
Read full description

A powerful MIDI modulation engine for controlling plugins, hardware, and instruments using LFOs, random sources, macros, and audio-based modulation. Modulate Everything MMM is a MIDI controller and modulation workstation designed to control any parameter that accepts MIDI CC — software instruments, plugins, external hardware, or any MIDI-capable device. Create modulation using LFOs, Random Generators, Envelope Followers, XY pads, and more. No more drawing of automation curves, keep your audio dynamic and exciting with ease. Perform Live MMM includes a dedicated Performance Skin designed for low-light and stage environments. It uses a restrained, red-accented color palette that preserves focus and minimizes visual distraction while performing. The interface remains clear and readable in dark settings, ensuring stable workflow during your live performance. MMM vs MMMm MMM includes audio input, enabling Envelope Followers, audio-reactive modulation, and audio output — ideal when used as an audio plugin. MMMm, by contrast, is a MIDI-only FX version for hosts such as Logic Pro or AUM that require a pure MIDI processor. Both versions support MIDI input and output and provide the same core modulators. MMM is an AUv3 audio effect plugin compatible with Logic Pro, AUM, Cubasis, GarageBand and many more. A Desktop version is also available for Windows and macOS (VST3 / AU / AAX). More information here: https://gs-dsp.com/products So what are you waiting for?

Screenshots

Holon4 screens
GSDSP MMM4 screens

Verdict

The call

The clearest difference is in-app purchases: GSDSP MMM at none against Holon's 2. GSDSP MMM also leads on rating (4.7 vs 4.5) and update cadence (every 5 weeks vs every 3 months). Holon's advantage is review sentiment (75% vs 67%). On price, ratings volume, ads 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

Both are free to download. Holon sells 2 one-off in-app purchases. GSDSP MMM asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

GSDSP MMM holds the better App Store score, 4.7 against 4.5. Both are backed by a comparable volume of ratings — 14 and 36 respectively. Written reviews complicate that: 75% of Holon's written reviews are positive against 67% of GSDSP MMM's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Holon ships an update every 3 months, GSDSP MMM every 5 weeks. The most recent releases landed on October 19, 2026 and October 27, 2026 respectively.

Scorecard5 real differences · 5 level
Holon versus GSDSP MMM: the parameters behind the verdict, then further details
ParameterHolonGSDSP MMM
PriceFreeFree
Rating4.5 (14 ratings)4.7 (36 ratings) — better
Positive reviews75.0% of reviews — better66.7% of reviews
Number of ratings1436 — better
Update frequencyEvery 3 monthsEvery 5 weeks — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationPaidFree — better
DevicesiPhone, iPad, iPod, Apple Watch — betteriPhone, iPad, iPod
Requires iOS12.0 — better13.0
Further details — not scored
Size144 MB65 MB
Age rating4+4+
DeveloperHolonic Systems OyGustav Scholda

Customer experience

Holon

All ratings14 ratings
Positive85.7%
Neutral7.1%
Negative7.1%
Written reviews12 reviews
Positive75.0%
Neutral8.3%
Negative16.7%

GSDSP MMM

All ratings36 ratings
Positive94.4%
Neutral0.0%
Negative5.6%
Written reviews6 reviews
Positive66.7%
Neutral0.0%
Negative33.3%

In-app purchases

2 purchases

Holon

One-time2
  • Apple Watch supportFree
  • Movesense SupportFree
None

GSDSP MMM

No in-app purchases

Questions

Is Holon free?
Holon is free to download, with in-app purchases available.
Is GSDSP MMM free?
GSDSP MMM is free to download, with no in-app purchases.
Which has better reviews, Holon or GSDSP MMM?
GSDSP MMM is rated higher. Holon averages 4.5 out of 5 from 14 ratings, while GSDSP MMM averages 4.7 from 36 ratings.
Do Holon or GSDSP MMM have ads?
Neither Holon nor GSDSP MMM shows ads.
Which is updated more often, Holon or GSDSP MMM?
Holon ships an update every 3 months, and GSDSP MMM every 5 weeks. Most recently, Holon was updated on October 19, 2026 and GSDSP MMM on October 27, 2026.

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