# Retromulator vs SJ

The clearest difference is price: SJ at $0.49 against Retromulator's $29.99. Retromulator's advantage is update cadence (every 3 days vs fortnightly) and iOS requirement (16.0 vs 26.5). On ads, in-app purchases and device support there is nothing between them.

Retromulator costs $29.99 and SJ $0.49 up front. Neither carries in-app purchases, so what you see is what you pay.

Retromulator ships an update every 3 days, SJ fortnightly. The most recent releases landed on November 9, 2026 and November 10, 2026 respectively.

## The numbers

| Metric | Retromulator | SJ |
| --- | --- | --- |
| Price | $29.99 | **$0.49** |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/retromulator/id6764767449/reviews)** | — |
| Number of ratings | **4** | — |
| Positive reviews | 62.5% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 days** | Fortnightly |
| Monetization | Paid | — |
| Size | 138 MB | 30 MB |
| Requires iOS | **16.0** | 26.5 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [DiscoDSP LLC](https://appshunter.io/developer/1465262828) | [Kouki Yoshimoto](https://appshunter.io/developer/1884780659) |

## What reviewers say

### Retromulator

[App page](https://appshunter.io/ios/app/retromulator/id6764767449)

This app offers authentic low-level emulation of legendary hardware synthesizers, samplers, and keyboards. It brings classic electronic music instruments back to life with their original firmware and behavior, supporting various core emulations for diverse sound creation.

**Highlights:** Multi-core retro hardware emulation, AUv3 plug-in support, Authentic low-level emulation of original firmware, Virtual analog, FM, and chiptune synthesis, GM/GS sound modules, Organ and electric piano emulation

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

**In-app purchases:** none


### SJ

[App page](https://appshunter.io/ios/app/sj-square-synthesizer/id6797394418)

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

**In-app purchases:** none


## Frequently asked questions

### Is Retromulator free?

Retromulator costs $29.99, with no in-app purchases.

### Is SJ free?

SJ costs $0.49, with no in-app purchases.

### Do Retromulator or SJ have ads?

Neither Retromulator nor SJ shows ads.

### Which is updated more often, Retromulator or SJ?

Retromulator ships an update every 3 days, and SJ fortnightly. Most recently, Retromulator was updated on November 9, 2026 and SJ on November 10, 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.*