Theremin I/O vs Polybeep
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- Touchless instrument control via camera
- Adjustable scales and harmony quantization
- Multiple sound presets with effects
- MIDI controller functionality (in-app purchase)
- Interactive tutorial overlay
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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
Polybeep
Create unique music with a polyrhythmic sound machine. Record or load samples, arrange them into looping shapes, and apply various effects. MIDI input is supported, and songs can be exported as WAV files.
- Polyrhythmic sound generation
- Record microphone audio
- Load sample files
- Looping shape arrangement
- Extensive audio effects
- MIDI input support
- Export to WAV
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From the creators of DefleMask and Minimic, introducing Polybeep, a magnificent polyrhythmic sound machine designed to unlock your creativity. We even prepared a built-in tutorial to get you started. With aesthetically pleasing colors and design alongside unmatched visual feedback, you can really feel the beeping beeps and the poly rhythms. Yes, you can set up polyrhythms as easy as 3-4-5. You can record sounds directly from your microphone or load sample files. There’s some magic to make them sound great. Arrange the sounds into up to 6 looping shapes that can be configured as polygons of 3~16 vertices, then tweak their effects (delay, reverb, EQ, panning, chorus, and more), make a sequence of many melodies, and you’ll have a song in no time! You can even tap to change the tempo based on a rhythmic pulse. MIDI device input is as well supported! MIDI output coming soon! (notes, sync) macOS version is also available! Polybeep has been designed with a touch screen in mind from day one but it works perfectly fine on computers. When ready, you can save your songs and export them to wav files. We’d love to hear the songs that you come up with!
Screenshots
Verdict
The clearest difference is rating: Polybeep at 4.7 against Theremin I/O's 4.0. Polybeep also leads on in-app purchases (none vs 1) and update cadence (fortnightly vs every 24 months). Theremin I/O's advantage is review sentiment (77% vs 50%) and chart position (#163 vs unranked). On ratings volume, ads, 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
Theremin I/O costs $2.99 and Polybeep $4.99 up front. Theremin I/O sells 1 one-off in-app purchase. Polybeep asks for nothing beyond the download.
Polybeep holds the better App Store score, 4.7 against 4.0. Both are backed by a comparable volume of ratings — 5 and 3 respectively. Written reviews complicate that: 77% of Theremin I/O's written reviews are positive against 50% of Polybeep's, so the app with the better star average is not the one people write more warmly about.
Theremin I/O ships an update every 24 months, Polybeep fortnightly. The most recent releases landed on October 12, 2026 and September 30, 2026 respectively.
| Parameter | Theremin I/O | Polybeep |
|---|---|---|
| Price | $2.99 — better | $4.99 |
| Rating | 4.0 (5 ratings) | 4.7 (3 ratings) — better |
| Positive reviews | 76.9% of reviews — better | 50.0% of reviews |
| Number of ratings | 5 — better | 3 |
| Update frequency | Every 24 months | Fortnightly — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Paid | Paid |
| Best chart rank | #163 — better | — |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 8.0 — better | 12.0 |
| Further details — not scored | ||
| Size | 18 MB | 101 MB |
| Age rating | +4 | 4+ |
| Developer | FFFF00 Agents AB | Leonardo Demartino |
Customer experience
Theremin I/O
Polybeep
In-app purchases
Theremin I/O
- Network MIDI$5.99
Polybeep
No in-app purchases









