# sumFX vs OTOKAI

The clearest difference is review sentiment: sumFX at 50% against OTOKAI's 0%. sumFX also leads on iOS requirement (12.0 vs 15.5). OTOKAI's advantage is price (Free vs $9.99) and update cadence (weekly vs every 6 months). On ads, in-app purchases and device support there is nothing between them.

OTOKAI is free to download; sumFX costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

sumFX ships an update every 6 months, OTOKAI weekly. The most recent releases landed on November 3, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | sumFX | OTOKAI |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | **[4.4 (12 ratings)](https://appshunter.io/ios/app/sumfx/id6450494474/reviews)** | — |
| Number of ratings | **12** | — |
| Positive reviews | **50.0% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Weekly** |
| Monetization | Paid | **Free** |
| Size | 44 MB | 93 MB |
| Requires iOS | **12.0** | 15.5 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [OSC Audio](https://appshunter.io/developer/1693533681) | [Amadeus Code Inc.](https://appshunter.io/developer/802869982) |

## What reviewers say

### sumFX

[App page](https://appshunter.io/ios/app/sumfx/id6450494474)

This app is a versatile audio effects processor for musicians. It offers a modular design with multiple high-quality FX modules and customizable slots, allowing for quick creation of unique sounds. Focus on your music with intuitive controls and visual feedback.

**Highlights:** Modular multi-FX processor, 8 high-quality FX modules, 8 FX slots with Wet/Dry control, 2 LFOs per slot, 50+ cross-platform presets, Pre/post waveform view

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

**In-app purchases:** none


### OTOKAI

[App page](https://appshunter.io/ios/app/otokai/id6499198233)

Engage your mind and brain with music through interactive listening, creative expression, and social connection. This app encourages active participation by comparing tracks, articulating feelings, and combining music with photos or videos. It fosters cognitive health and social well-being in a private environment.

**Highlights:** Interactive music listening, Create music and photo/video combinations, Closed social network for sharing, Brain activity enhancement, Daily brain health habit, Private and safe environment

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

**In-app purchases:** none


## Frequently asked questions

### Is sumFX free?

sumFX costs $9.99, with no in-app purchases.

### Is OTOKAI free?

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

### Do sumFX or OTOKAI have ads?

Neither sumFX nor OTOKAI shows ads.

### Which is updated more often, sumFX or OTOKAI?

sumFX ships an update every 6 months, and OTOKAI weekly. Most recently, sumFX was updated on November 3, 2026 and OTOKAI on November 4, 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.*