# Synesthesia Synth vs ThereminAir

The clearest difference is price: Synesthesia Synth at Free against ThereminAir's $3.99. On rating, ratings volume, update cadence and ads there is nothing between them.

Synesthesia Synth is free to download; ThereminAir costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for Synesthesia Synth against 5.0 for ThereminAir. Both are backed by a comparable volume of ratings — 2 and 1 respectively.

Synesthesia Synth ships an update every 10 days, ThereminAir every 11 days. The most recent releases landed on October 19, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | Synesthesia Synth | ThereminAir |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| Rating | [5.0 (2 ratings)](https://appshunter.io/ios/app/synesthesia-synth/id6763379132/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/thereminair-theremin-synth/id6772935515/reviews) |
| Number of ratings | **2** | 1 |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 10 days** | Every 11 days |
| Monetization | Free | Free |
| Size | 141 MB | 2 MB |
| Requires iOS | **16.0** | 17.0 |
| Devices | iPhone, iPad | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [MICHELE ZACCAGNINI](https://appshunter.io/developer/1895288560) | [Tom Pardee](https://appshunter.io/developer/1882976406) |

## What reviewers say

### Synesthesia Synth

[App page](https://appshunter.io/ios/app/synesthesia-synth/id6763379132)

An experimental audio-visual instrument that allows users to sculpt evolving spatial audio by manipulating floating capsules. Position, rotation, and pulse changes affect tone, texture, and synchronized particle generation. It's a visual synthesizer, not a game.

**Highlights:** Experimental audio-visual instrument, Sculpt evolving spatial audio, Manipulate floating capsules, Control tone, texture, and particles, Visual synthesizer

**In-app purchases:** none


### ThereminAir

[App page](https://appshunter.io/ios/app/thereminair-theremin-synth/id6772935515)

This app transforms your Apple Watch into a unique theremin instrument. Play music through arm gestures, controlling pitch and volume without touching any buttons. Explore different modes and scales to create a variety of sounds.

**Highlights:** Gesture-based pitch and volume control, Pure mode for continuous glide, Scale modes for staying in tune, Adjustable pitch ranges and vibrato depths, Live readout of frequency and note name, Complication for instant play

**Features:** Apple Watch app

**In-app purchases:** none


## Frequently asked questions

### Is Synesthesia Synth free?

Synesthesia Synth is free to download, with no in-app purchases.

### Is ThereminAir free?

ThereminAir costs $3.99, with no in-app purchases.

### Which has better reviews, Synesthesia Synth or ThereminAir?

Synesthesia Synth and ThereminAir are both rated 5.0 out of 5 on the App Store, from 2 and 1 ratings respectively.

### Do Synesthesia Synth or ThereminAir have ads?

Neither Synesthesia Synth nor ThereminAir shows ads.

### Which is updated more often, Synesthesia Synth or ThereminAir?

Synesthesia Synth ships an update every 10 days, and ThereminAir every 11 days. Most recently, Synesthesia Synth was updated on October 19, 2026 and ThereminAir on October 11, 2026.

---

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