Comparison

Theremin I/O vs Pixel Music

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

Head to head
About

Theremin I/O

Transform your iPhone into a touchless musical instrument using your camera and flash. Control sound generation by hand proximity, with options for scales, sound presets, and effects. An in-app purchase enables MIDI controller functionality.

Highlights
  • Touchless instrument control via camera
  • Adjustable scales and harmony quantization
  • Multiple sound presets with effects
  • MIDI controller functionality (in-app purchase)
  • Interactive tutorial overlay
Features
Read full description

Play with light – Theremin I/O turns your iPhone into a touchless music instrument. It uses your camera and flash to measure the distance to your hand, this signal is then processed by a synthesizer to generate a tone. Features: • Old-school synthesizer • Constrain input to scales (harmony quantization) • 8 sound presets with effect controls • 50+ scale presets • Use as a MIDI controller (requires in-app purchase) • Learn fast with the tutorial overlay For more information visit http://theremin.io

About

Pixel Music

Transform your favorite images into unique musical compositions. This app uses pixel data to control pitch, duration, and velocity, allowing you to create melodies and rhythms by interacting with visuals. Explore various traversal methods and image data types for diverse sonic results.

Highlights
  • Pixels control pitch, velocity, and note duration
  • Play multiple images simultaneously
  • AUv3 support with MIDI
  • Ableton Link compatible
  • Customizable image traversal and data mapping
  • Internal synth with effects
  • Save and load app states
Features
Read full description

Pixel Music is a music sequencer based on images. Take an image you love and start playing. Overview ◦ Pixels turn into pitch, velocity, and note durations ◦ Play multiple images at the same time, in sync ◦ Choose what parts of the image will be played and at what timing ◦ Tap on the image and record yourself playing alongside the sequencer Features ◦ AUv3 with preset and MIDI support ◦ Ableton Link compatible ◦ Control sequencer timing and configuration ◦ Program different step lengths in patterns and play these across your images with Verses ◦ Choose between RGB, Luminance, Hue, or Saturation data to control pitch, velocity, or note duration ◦ Choose how the image is traversed, between Left -> Right, Top -> Down, or Circular. Select randomness factor in image traversal ◦ Choose recorded loop length and quantization settings ◦ Internal Synth with delay and reverb effects ◦ Send MIDI to external synths when used as AUv3. Each image you add has a separate MIDI channel exposed in the AU host ◦ Save and Load app states and configurations ◦ Dark mode support AU Hosts Compatibility ◦ Pixel Music works best with AUM, Audiobus, or ApeMatrix ◦ Pixel Music does NOT support Logic Pro or Garage Band Have fun with it.

Screenshots

Theremin I/O3 screens
Pixel Music4 screens

Verdict

The call

The clearest difference is rating: Pixel Music at 4.6 against Theremin I/O's 4.0. Pixel Music also leads on in-app purchases (none vs 1) and update cadence (every 8 months vs every 24 months). Theremin I/O's advantage is price ($2.99 vs $5.99) and iOS requirement (8.0 vs 13.0). On review sentiment, ratings volume, 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

Theremin I/O costs $2.99 and Pixel Music $5.99 up front. Theremin I/O sells 1 one-off in-app purchase. Pixel Music asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Pixel Music holds the better App Store score, 4.6 against 4.0. Both are backed by a comparable volume of ratings — 5 and 7 respectively. Written reviews point the same way: 77% of Theremin I/O's written reviews are positive against 82% of Pixel Music's.

UpkeepUpdate frequency

Theremin I/O ships an update every 24 months, Pixel Music every 8 months. The most recent releases landed on October 26, 2026 and October 24, 2026 respectively.

Scorecard5 real differences · 5 level
Theremin I/O versus Pixel Music: the parameters behind the verdict, then further details
ParameterTheremin I/OPixel Music
Price$2.99 — better$5.99
Rating4.0 (5 ratings)4.6 (7 ratings) — better
Positive reviews76.9% of reviews81.8% of reviews — better
Number of ratings57 — better
Update frequencyEvery 24 monthsEvery 8 months — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationPaidPaid
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS8.0 — better13.0
Further details — not scored
Size18 MB39 MB
Age rating+44+
DeveloperFFFF00 Agents ABAndrei Antonescu

Customer experience

Theremin I/O

All ratings5 ratings
Positive60.0%
Neutral20.0%
Negative20.0%
Written reviews13 reviews
Positive76.9%
Neutral15.4%
Negative7.7%

Pixel Music

All ratings7 ratings
Positive85.7%
Neutral14.3%
Negative0.0%
Written reviews11 reviews
Positive81.8%
Neutral9.1%
Negative9.1%

In-app purchases

1 purchases

Theremin I/O

One-time1
  • Network MIDI$5.99
None

Pixel Music

No in-app purchases

Questions

Is Theremin I/O free?
Theremin I/O costs $2.99, and also offers in-app purchases.
Is Pixel Music free?
Pixel Music costs $5.99, with no in-app purchases.
Which has better reviews, Theremin I/O or Pixel Music?
Pixel Music is rated higher. Theremin I/O averages 4.0 out of 5 from 5 ratings, while Pixel Music averages 4.6 from 7 ratings.
Do Theremin I/O or Pixel Music have ads?
Neither Theremin I/O nor Pixel Music shows ads.
Which is updated more often, Theremin I/O or Pixel Music?
Theremin I/O ships an update every 24 months, and Pixel Music every 8 months. Most recently, Theremin I/O was updated on October 26, 2026 and Pixel Music on October 24, 2026.

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