Comparison

MIDI FX vs GSDSP MMMm

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

Head to head
About

MIDI FX

This app allows you to control and process MIDI signals for music creation. It offers features like harmonization, transposition, and sequencing, enabling you to control external or virtual synthesizers and create complex musical arrangements.

Highlights
  • MIDI signal processing
  • Harmonize and Transpose
  • Sequencer for synths
  • Delay and Looper
  • Filter notes by velocity
  • Internal instruments
Features
Read full description

Buy once and get the iOS and Mac apps (with Family Sharing) Control your MIDI signals and process them in any combination of ways: Harmonize, Transpose, Arpeggiate, etc... Or use the Sequencer to play any external or virtual synth. Use a MIDI interface to unlock the power of the app to control multiple synths with one keyboard, play one note and generate chords, basslines, etc... Use the delay/looper or filter notes based on velocity or other parameters to send to different synths/effects. A MIDI workstation in your pocket (or your iPad/Mac) You can also use some internal instruments (drums sampler, piano or synth) if you are away from your MIDI gear, and sequence whole songs inside the app, or use other synth apps as input/output for MIDI FX. Your imagination is the limit!

About

GSDSP MMMm

This app provides a powerful MIDI modulation engine to control various plugins, hardware, and instruments. It offers a range of modulation sources like LFOs and random generators, and includes a dedicated performance skin for live use. It's a MIDI-only FX version for hosts requiring pure MIDI processing.

Highlights
  • MIDI CC control for plugins and hardware
  • LFO, Random, Envelope Follower modulators
  • XY pads for modulation
  • Dedicated Performance Skin for live use
  • AUv3 MIDI FX plugin
  • Desktop versions available
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 MMMm 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 MMMm 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. MMMm is an AUv3 midi 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

Screenshots

MIDI FX2 screens
GSDSP MMMm4 screens

Verdict

The call

The clearest difference is in-app purchases: GSDSP MMMm at none against MIDI FX's 1. GSDSP MMMm also leads on ratings volume (16 vs 5). MIDI FX's advantage is update cadence (every 9 days vs every 5 weeks). On price, rating, ads 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. MIDI FX sells 1 one-off in-app purchase. GSDSP MMMm asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for MIDI FX against 4.9 for GSDSP MMMm. Both are backed by a comparable volume of ratings — 5 and 16 respectively.

UpkeepUpdate frequency

MIDI FX ships an update every 9 days, GSDSP MMMm every 5 weeks. The most recent releases landed on October 23, 2026 and October 27, 2026 respectively.

Scorecard3 real differences · 7 level
MIDI FX versus GSDSP MMMm: the parameters behind the verdict, then further details
ParameterMIDI FXGSDSP MMMm
PriceFreeFree
Rating5.0 (5 ratings) — better4.9 (16 ratings)
Positive reviews—100.0% of reviews
Number of ratings516 — better
Update frequencyEvery 9 days — betterEvery 5 weeks
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreeFree
DevicesiPhone, iPad, iPod, Mac — betteriPhone, iPad, iPod
Requires iOS14.713.0 — better
Further details — not scored
Size263 MB44 MB
Age rating4+4+
DeveloperJorge ArroyoGustav Scholda

Customer experience

MIDI FX

All ratings4 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

GSDSP MMMm

All ratings16 ratings
Positive93.8%
Neutral6.3%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

1 purchases

MIDI FX

One-time1
  • Unlock app$9.99
None

GSDSP MMMm

No in-app purchases

Questions

Is MIDI FX free?
MIDI FX is free to download, with in-app purchases available.
Is GSDSP MMMm free?
GSDSP MMMm is free to download, with no in-app purchases.
Which has better reviews, MIDI FX or GSDSP MMMm?
MIDI FX is rated higher. MIDI FX averages 5.0 out of 5 from 5 ratings, while GSDSP MMMm averages 4.9 from 16 ratings.
Do MIDI FX or GSDSP MMMm have ads?
Neither MIDI FX nor GSDSP MMMm shows ads.
Which is updated more often, MIDI FX or GSDSP MMMm?
MIDI FX ships an update every 9 days, and GSDSP MMMm every 5 weeks. Most recently, MIDI FX was updated on October 23, 2026 and GSDSP MMMm on October 27, 2026.

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