# ButterSynth vs ECHO

The clearest difference is price: ButterSynth at $19.99 against ECHO's $129.99. ECHO's advantage is update cadence (every 2 weeks vs every 2 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

ButterSynth costs $19.99 and ECHO $129.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ButterSynth ships an update every 2 months, ECHO every 2 weeks. The most recent releases landed on October 16, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | ButterSynth | ECHO |
| --- | --- | --- |
| Price | **$19.99** | $129.99 |
| Rating | **[4.0 (63 ratings)](https://appshunter.io/ios/app/buttersynth/id1497419006/reviews)** | — |
| Number of ratings | **63** | — |
| Positive reviews | 59.2% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Monetization | Paid | — |
| Size | 468 MB | 13 MB |
| Requires iOS | **14.0** | 15 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, iPod, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Arto Vaarala](https://appshunter.io/developer/890886114) | [Gentian Coci](https://appshunter.io/developer/1809578428) |

## What reviewers say

### 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


### ECHO

[App page](https://appshunter.io/ios/app/echo-terza/id6752669555)

**In-app purchases:** none


## Frequently asked questions

### Is ButterSynth free?

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

### Is ECHO free?

ECHO costs $129.99, with no in-app purchases.

### Do ButterSynth or ECHO have ads?

Neither ButterSynth nor ECHO shows ads.

### Which is updated more often, ButterSynth or ECHO?

ButterSynth ships an update every 2 months, and ECHO every 2 weeks. Most recently, ButterSynth was updated on October 16, 2026 and ECHO on October 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.*