# Subzero Radio vs Rithmatic

The clearest difference is in-app purchases: Subzero Radio at none against Rithmatic's 4. Subzero Radio also leads on iOS requirement (13.0 vs 15.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Rithmatic sells 4 one-off in-app purchases. Subzero Radio asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 2 days. The most recent releases landed on October 6, 2026 and November 1, 2026 respectively.

## The numbers

| Metric | Subzero Radio | Rithmatic |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.6 (9 ratings)](https://appshunter.io/ios/app/rithmatic-fm-synth/id6794107110/reviews)** |
| Number of ratings | — | **9** |
| Positive reviews | — | 66.7% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 days | Every 2 days |
| Monetization | — | Free |
| Size | 104 MB | 61 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [sheraz Rasheed](https://appshunter.io/developer/1487019876) | [MADE WITH BEST PRACTICE LLC](https://appshunter.io/developer/6779338119) |

## What reviewers say

### Subzero Radio

[App page](https://appshunter.io/ios/app/subzero-radio/id6772709625)

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

**In-app purchases:** none


### Rithmatic

[App page](https://appshunter.io/ios/app/rithmatic-fm-synth/id6794107110)

This app is an FM synthesizer with a vast library of classic voices. It allows users to explore, learn, build, and blend sounds, and can be used as a standalone instrument or an AUv3 plugin within DAWs. It offers a visual representation of sound and a patch builder for understanding FM synthesis.

**Highlights:** 36,118 classic DX7 voices included, AUv3 plugin for DAWs, Patch Builder for learning FM synthesis, Sound blending feature, On-screen and MIDI keyboard support, Arpeggiator and latch functionality, WAV recording and export

**Features:** Vision Pro support, iPhone Duo support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Small Tip | $4.99 | one-time |
| Medium Tip | $9.99 | one-time |
| Large Tip | $19.99 | one-time |
| Extra Large Tip | $49.99 | one-time |


## Frequently asked questions

### Is Subzero Radio free?

Subzero Radio is free to download, with no in-app purchases.

### Is Rithmatic free?

Rithmatic is free to download, with in-app purchases available.

### Do Subzero Radio or Rithmatic have ads?

Neither Subzero Radio nor Rithmatic shows ads.

### Which is updated more often, Subzero Radio or Rithmatic?

Subzero Radio ships an update every 2 days, and Rithmatic every 2 days. Most recently, Subzero Radio was updated on October 6, 2026 and Rithmatic on November 1, 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.*