Comparison

sumFX vs OTOKAI

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

sumFX

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
Read full description

sumFX is a modular multi-FX processor for Mac/PC and iOS. Designed with simplicity in mind, to help keep you focused on the music and the sum of your efforts. Packed with 8 high quality FX modules and an available 8 slots, each loaded with Wet/Dry control, Global Wet/Dry, and 2 LFOs per slot, creating new unique sounds is quick and easy. 50+ cross-platform slot & chain presets are included to get you to any sound you need quickly and we’ve packed in an easy to use pre/post waveform view to help keep you focused on the result of your FX. Modules: -syncDynamics - Multimode dynamic FX with BPM sync attack/release (Noise Gate, Expander, Compressor, Limiter) -stereoFilter - Stereo filter with link or individual channel controls (LPF12, HPF12, BPF12, LPF24, HPF24, BPF24, Notch, & Formant options). -variMod - Multimode modulation FX with stereo offset (Chorus, Flanger,  Vibrato, Phaser, Tremolo,  & Auto Pan) -EQuator - Full high quality EQ module (3 Parametric Bands, High/Low Shelf, & HPF/LPF). -frostReverb - Multi-Mode (Original, Plate, Spring, Room) Stereo Reverb.  -bucketDelay - Stereo Analog Style Delay with individual channel control. -variPitch - Stereo Pitch Shifter with 3X Modes (Doubler, Harmonizer, & Full Control) -powerPhase - Multimode Saturation, Utility Gain In/Out, Mono Maker, Channel msDelay, & Phase inverter.

About

OTOKAI

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
Read full description

OTOKAI is an app designed to help you keep both your mind and brain active by enjoying music, using your brain, and staying connected with family and friends. Rather than simply listening to music, OTOKAI encourages you to compare different tracks, make choices, and put what you feel into words. You can also combine music with photos or videos to create your own works. Through the music you enjoy, OTOKAI helps you build a natural habit of using your brain. OTOKAI also includes a closed social network where you can share your creations and thoughts with family and friends. In a safe and private environment, you can stay connected with the people who matter to you and enjoy conversations and shared experiences. Social interaction can support not only emotional well-being, but also the maintenance of cognitive function. The music featured in OTOKAI uses MusicTGA, Amadeus Code’s proprietary technology developed through years of research into the structural patterns of hit songs. By providing a music experience that naturally makes you want to keep listening, OTOKAI supports brain activity while making the experience enjoyable. OTOKAI is designed as a daily brain health habit aimed at helping maintain cognitive function. In our first pilot study, continued participation was associated with improvements in frontal lobe function among older adults. https://otokai.jp/en/specialist/ Music for a healthier mind and brain. Start your daily brain health routine with OTOKAI.

Screenshots

sumFX3 screens
OTOKAI4 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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

UpkeepUpdate frequency

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

Scorecard5 real differences · 5 level
sumFX versus OTOKAI: the parameters behind the verdict, then further details
ParametersumFXOTOKAI
Price$9.99Free — better
Rating4.4 (12 ratings) — better—
Positive reviews50.0% of reviews — better0.0% of reviews
Number of ratings12 — better—
Update frequencyEvery 6 monthsWeekly — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidFree — better
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS12.0 — better15.5
Further details — not scored
Size44 MB93 MB
Age rating4+4+
DeveloperOSC AudioAmadeus Code Inc.

Customer experience

sumFX

All ratings12 ratings
Positive83.3%
Neutral8.3%
Negative8.3%
Written reviews12 reviews
Positive50.0%
Neutral16.7%
Negative33.3%

OTOKAI

Written reviews1 reviews
Positive0.0%
Neutral100.0%
Negative0.0%

In-app purchases

None

sumFX

No in-app purchases

None

OTOKAI

No in-app purchases

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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