# SWAM Viola vs ButterSynth

The clearest difference is price: ButterSynth at $19.99 against SWAM Viola's $29.99. ButterSynth also leads on ratings volume (63 vs 6). SWAM Viola's advantage is review sentiment (100% vs 59%) and rating (4.3 vs 4.0). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

SWAM Viola costs $29.99 and ButterSynth $19.99 up front. Neither carries in-app purchases, so what you see is what you pay.

SWAM Viola holds the better App Store score, 4.3 against 4.0. That said, the two scores are not equally well evidenced: ButterSynth has 63 ratings behind it against 6, so its average is the more settled of the two. Written reviews point the same way: 100% of SWAM Viola's written reviews are positive against 59% of ButterSynth's.

SWAM Viola ships an update every 5 weeks, ButterSynth every 2 months. The most recent releases landed on October 25, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | SWAM Viola | ButterSynth |
| --- | --- | --- |
| Price | $29.99 | **$19.99** |
| Rating | **[4.3 (6 ratings)](https://appshunter.io/ios/app/swam-viola/id1458130582/reviews)** | [4.0 (63 ratings)](https://appshunter.io/ios/app/buttersynth/id1497419006/reviews) |
| Number of ratings | 6 | **63** |
| Positive reviews | **100.0% of reviews** | 59.2% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 5 weeks** | Every 2 months |
| Monetization | Paid | Paid |
| Size | 103 MB | 468 MB |
| Requires iOS | 15.0 | **14.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Audio Modeling](https://appshunter.io/developer/1326331126) | [Arto Vaarala](https://appshunter.io/developer/890886114) |

## What reviewers say

### SWAM Viola

[App page](https://appshunter.io/ios/app/swam-viola/id1458130582)

This virtual instrument uses physical modeling to generate realistic string performances in real-time, responding dynamically to your playing style. It offers advanced spatial control with a built-in room simulator and can be used standalone or as an AUv3 plugin. Designed for expressive control, it's suitable for various musical styles and accessible to visually impaired users.

**Highlights:** Physical modeling sound generation, Real-time dynamic response, Built-in Room Simulator (Ambiente), Standalone and AUv3 plugin support, Intuitive interface for all users, MPE and MIDI controller support, Customizable timbre, vibrato, and dynamics

**In-app purchases:** none


### ButterSynth

[App page](https://appshunter.io/ios/app/buttersynth/id1497419006)

This powerful synthesizer app offers a hybrid approach, combining wavetable, FM, and sample-based synthesis. Create unique sounds with a vast sonic range, advanced modulation, and a built-in effects rack. It caters to both experienced sound designers and beginners with extensive presets.

**Highlights:** Hybrid 6-oscillator synthesis (wavetable, FM, sample), Built-in wavetable editor, FM engine with 4 operators, Sample and Granulator engines, 32-slot modulation matrix, Internal FX rack with 16 modules, Extensive preset library

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- ✨ Deep sound design capabilities
- 🎛️ Versatile modulation matrix
- 🔊 Great sound quality
- 💡 Innovative wavetable generator
- 🌟 Serum-like experience

**What reviewers complain about**

- 📱 Fiddly on small screens
- 🐛 Crashes frequently
- 🐛 Disappears in Cubasis
- 🐛 Spikes CPU usage
- 🐛 Crashes on patch change

**Reported bugs**

- App crashing with AUM
- Disappears in Cubasis randomly
- Crashes all the time inside Logic
- Changing a patch spikes CPU to 99%
- Crashes on every patch change

**Requested features**

- MPE popup possible on top of the auv3
- Button to hide built-in keyboard
- Buffer size option
- Additional MIDI mappings (e.g., arpeggiator toggle)
- Sustain pedal support


## Frequently asked questions

### Is SWAM Viola free?

SWAM Viola costs $29.99, with no in-app purchases.

### Is ButterSynth free?

ButterSynth costs $19.99, with no in-app purchases.

### Which has better reviews, SWAM Viola or ButterSynth?

SWAM Viola is rated higher. SWAM Viola averages 4.3 out of 5 from 6 ratings, while ButterSynth averages 4.0 from 63 ratings.

### Do SWAM Viola or ButterSynth have ads?

Neither SWAM Viola nor ButterSynth shows ads.

### Which is updated more often, SWAM Viola or ButterSynth?

SWAM Viola ships an update every 5 weeks, and ButterSynth every 2 months. Most recently, SWAM Viola was updated on October 25, 2026 and ButterSynth on October 27, 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.*