# S vs Callback Freeverb

The clearest difference is rating: Callback Freeverb at 5.0 against S's 4.5. S's advantage is ratings volume (4 vs 1). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Callback Freeverb holds the better App Store score, 5.0 against 4.5. Both are backed by a comparable volume of ratings — 4 and 1 respectively.

## The numbers

| Metric | S | Callback Freeverb |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.5 (4 ratings)](https://appshunter.io/ios/app/s-2/id6769518675/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/callback-freeverb/id6775060495/reviews)** |
| Number of ratings | **4** | 1 |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 weeks | — |
| Monetization | Free | Free |
| Size | 17 MB | 7 MB |
| Requires iOS | **16.0** | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Mathias Kirkerød](https://appshunter.io/developer/1884969842) | [Callback Audio, LLC](https://appshunter.io/developer/1896220942) |

## What reviewers say

### S

[App page](https://appshunter.io/ios/app/s-2/id6769518675)

This app is a polyphonic synthesizer that works with specific hardware. It offers a variety of sound engines, filters, and effects for creating unique audio textures. Advanced modulation options and a flexible routing system allow for deep sound design.

**Highlights:** Dual engine slots per voice, Multiple sound flavors (analog, wavetable, FM, speech), Classic and Modern filter modes, Advanced FX rack, Two free-routing LFOs, Unified mod matrix, Standalone, AU, and AUv3 formats

**Features:** macOS Compatibility

**In-app purchases:** none


### Callback Freeverb

[App page](https://appshunter.io/ios/app/callback-freeverb/id6775060495)

This app offers a classic algorithmic reverb effect based on the Freeverb algorithm. It adds depth, space, and atmosphere to audio sources, creating lush, spacious ambience. Designed for mono use, it provides a smooth, musical reverb tail suitable for vocals and synthesizers.

**Highlights:** Classic Freeverb algorithm, Schroeder/Moorer reverb topology, Comb and allpass filters, Mono operation, Adds depth and space to audio, Smooth, musical reverb tail

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is S free?

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

### Is Callback Freeverb free?

Callback Freeverb is free to download, with no in-app purchases.

### Which has better reviews, S or Callback Freeverb?

Callback Freeverb is rated higher. S averages 4.5 out of 5 from 4 ratings, while Callback Freeverb averages 5.0 from 1 ratings.

### Do S or Callback Freeverb have ads?

Neither S nor Callback Freeverb shows ads.

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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.*