# Theremin I/O vs Polybeep

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 (#184 vs unranked). On ratings volume, ads, monetization model and device support there is nothing between them.

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.

## The numbers

| Metric | Theremin I/O | Polybeep |
| --- | --- | --- |
| Price | **$2.99** | $4.99 |
| Rating | [4.0 (5 ratings)](https://appshunter.io/ios/app/theremin-io/id669456913/reviews) | **[4.7 (3 ratings)](https://appshunter.io/ios/app/polybeep/id6471223455/reviews)** |
| Number of ratings | **5** | 3 |
| Positive reviews | **76.9% of reviews** | 50.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 24 months | **Fortnightly** |
| Monetization | Paid | Paid |
| Best chart rank | **#184** | — |
| Size | 18 MB | 101 MB |
| Requires iOS | **8.0** | 12.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | +4 | 4+ |
| Developer | [FFFF00 Agents AB](https://appshunter.io/developer/288966262) | [Leonardo Demartino](https://appshunter.io/developer/1390797125) |

## What reviewers say

### Theremin I/O

[App page](https://appshunter.io/ios/app/theremin-io/id669456913)

**Currently charting:** #184 Top Paid · Music (US App Store)

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:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Network MIDI | $5.99 | one-time |


### Polybeep

[App page](https://appshunter.io/ios/app/polybeep/id6471223455)

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.

**Highlights:** Polyrhythmic sound generation, Record microphone audio, Load sample files, Looping shape arrangement, Extensive audio effects, MIDI input support, Export to WAV

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Theremin I/O free?

Theremin I/O costs $2.99, and also offers in-app purchases.

### Is Polybeep free?

Polybeep costs $4.99, with no in-app purchases.

### Which has better reviews, Theremin I/O or Polybeep?

Polybeep is rated higher. Theremin I/O averages 4.0 out of 5 from 5 ratings, while Polybeep averages 4.7 from 3 ratings.

### Do Theremin I/O or Polybeep have ads?

Neither Theremin I/O nor Polybeep shows ads.

### Which is updated more often, Theremin I/O or Polybeep?

Theremin I/O ships an update every 24 months, and Polybeep fortnightly. Most recently, Theremin I/O was updated on October 12, 2026 and Polybeep on September 30, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*