Comparison

Red Koto vs Koto Sim

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

Head to head
About

Red Koto

Explore a collection of 74 Koto tunings by a renowned virtuoso. Use it to tune your instrument by ear, study scales, or play along with unique compositions. The app features interactive strings and notes for an immersive musical experience.

Highlights
  • 74 Koto tunings
  • Tuning by ear
  • Scale study
  • Interactive string display
  • Plucked and picked sounds
  • Customizable tuning order
Features
Read full description

RedKoto is a growing collection of currently 74 tunings by Koto Virtuoso Chieko Mori.  Red Koto can be used for tuning the Instrument by ear, for studying scales, or for playing with the different tunings. These are the tunings for her compositions and for learning Koto Music at "Koto Studio" in Tokyo. The Score of each composition is available separately on demand. Sounds are played both picked with the left hand and plucked with the right hand using ivory picks.  The middle of the screen represents the 13 strings of the Koto, each string plays a plucked sound at the corresponding pitch. To the right of the string the note is shown, touching each note produces a picked sound. The order of the tunings can be re-arranged by long-pressing on a tuning in the list. Except where noted differently, tunings are based on a root note of 442 Hertz. CHIEKO MORI KOTO STUDIO https://www.kotostudio.com ONLINE STORE https://store.kotostudio.com

About

Koto Sim

Experience the authentic sound and feel of Japan's national string instrument. This app offers realistic koto tones, customizable interfaces, and multiple play modes for musicians and enthusiasts. Record and share your creations within an immersive simulation.

Highlights
  • Authentic koto sounds
  • Customizable interface and tuning
  • Three dynamic play modes
  • Built-in recorder
  • Screen recording for sharing
  • Immersive simulation environment
Features
Read full description

Step into the serene world of the koto, Japan's national string instrument, celebrated for its delicate tones and timeless beauty. Koto Sim brings the authentic sound and feel of this iconic instrument to your fingertips, offering a realistic and inspiring platform for musicians, learners, and music enthusiasts. About the Koto The koto is a traditional Japanese string instrument with a long, elegant body and movable bridges. Typically with 13 strings (though there are variations), it produces a bright, resonant sound that is both calming and expressive. Rooted in Japanese classical music, the koto has evolved into modern genres, creating a harmonious blend of tradition and innovation. Why You’ll Love Koto Sim Authentic Koto Sounds Enjoy meticulously sampled koto tones, capturing the instrument’s bright, resonant, and expressive character. Perfect for traditional Japanese melodies or exploring modern compositions. Customizable Interface Adjust the key layout, bridge positions, and even tuning settings with advanced controls like microtone adjustments and transpose. Whether you’re performing classic koto pieces or crafting a new tuning style, Koto Sim adapts effortlessly to your creative flow. Three Dynamic Play Modes Free Play Mode: Play multiple strings to create rich, layered harmonies and flowing melodies. Single Note Mode: Focus on individual strings — ideal for mastering traditional techniques and scales. Soft Release Mode: Add a natural fade-out effect for smooth, authentic performances. Record and Share Your Music Capture your koto music effortlessly with the built-in recorder — or go one step further and record your entire screen performance to share with the world. Whether for progress tracking, social media, or artistic expression, sharing is seamless and intuitive. Immersive Simulation Screen Dive into a visually detailed, lifelike simulation environment that replicates the experience of playing a real koto. The authentic layout and animations make every note feel genuine. What Makes Koto Sim Unique? True-to-Life Sound: Every note replicates the elegant, resonant tones of a real koto, offering an authentic musical experience. Cultural Significance: Immerse yourself in the heritage of Japanese classical music while exploring modern adaptations. Elegant Design: A sleek, intuitive interface ensures a seamless experience for musicians of all levels. Creative Freedom: From traditional koto melodies to experimental microtonal fusion, Koto Sim opens the door to limitless musical expression. Download Koto Sim today and let the graceful tones of the koto inspire your music!

Screenshots

Red Koto2 screens
Koto Sim4 screens

Verdict

The call

The clearest difference is price: Koto Sim at Free against Red Koto's $8.99. Koto Sim also leads on rating (5.0 vs 1.0) and update cadence (every 4 weeks vs every 6 months). Red Koto's advantage is in-app purchases (none vs 1) and ads (none vs shown). On device support and iOS requirement 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

Koto Sim is free to download; Red Koto costs $8.99 up front. Koto Sim sells 1 one-off in-app purchase. Red Koto asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Koto Sim holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 4 respectively.

UpkeepUpdate frequency

Red Koto ships an update every 6 months, Koto Sim every 4 weeks. The most recent releases landed on October 1, 2026 and October 24, 2026 respectively.

Scorecard7 real differences · 3 level
Red Koto versus Koto Sim: the parameters behind the verdict, then further details
ParameterRed KotoKoto Sim
Price$8.99Free — better
Rating1.0 (1 ratings)5.0 (4 ratings) — better
Positive reviews40.0% of reviews—
Number of ratings14 — better
Update frequencyEvery 6 monthsEvery 4 weeks — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.012.0 — better
Further details — not scored
Size29 MB125 MB
Age rating4+4+
DeveloperOliver GrimmAlper Kahriman

Customer experience

Red Koto

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews5 reviews
Positive40.0%
Neutral0.0%
Negative60.0%

Koto Sim

All ratings4 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Red Koto

No in-app purchases

1 purchases

Koto Sim

One-time1
  • Get Premium$8.99

Questions

Is Red Koto free?
Red Koto costs $8.99, with no in-app purchases.
Is Koto Sim free?
Koto Sim is free to download, with in-app purchases available.
Which has better reviews, Red Koto or Koto Sim?
Koto Sim is rated higher. Red Koto averages 1.0 out of 5 from 1 ratings, while Koto Sim averages 5.0 from 4 ratings.
Do Red Koto or Koto Sim have ads?
Koto Sim shows ads; Red Koto does not.
Which is updated more often, Red Koto or Koto Sim?
Red Koto ships an update every 6 months, and Koto Sim every 4 weeks. Most recently, Red Koto was updated on October 1, 2026 and Koto Sim on October 24, 2026.

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