Otosan

HIROSHI SHINKAWA Utilities iPhoneiPadiPod touch

Otosan is a free Utilities app for iPhone and iPad by HIROSHI SHINKAWA. Requires iOS 26.2. Updated October 29, 2026.

Price: Free; on the App Store
Size: 102 MB; Age 4+
Updated: Oct 29; 2026 · v1.6.1

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Screenshots

About Otosan

Enter any value from 20Hz to 20,000Hz to play your favorite frequency, or use the slider to test your hearing range. Frequencies like 432Hz and 528Hz are popular for relaxation, meditation, yoga, studying, and sleep. The built-in tuner also works great for tuning instruments. Simple design with a retro feel. Includes 3 bonus tracks: RetroTone_A440.0Hz / RetroTone_A432.0Hz / RTSHealing_A432.0Hz.

What’s new

Version 1.6.1 · Updated October 29, 2026

■We've renamed the app from "RetroTone" to "Otosan." It's the same app you know — just a new name. ■New: Binaural Beats — plays slightly different frequencies in each ear to help you relax or focus. Choose from Theta(5Hz)/Alpha(10Hz)/Beta(15Hz)/Gamma(40Hz) presets. Launch from the "Binaural" chip at the top (not intended as a medical device; effects are not guaranteed. Headphones recommended). Minor bug fixes and stability improvements.

App privacy

The developer, HIROSHI SHINKAWA, reported these privacy practices to Apple.

Data Linked to You

The following data, which may be collected and linked to your identity, may be used for the following purposes:

Identifiers: User ID, Device ID
Usage Data: Product Interaction
Diagnostics: Crash Data, Performance Data

Used for: Analytics, App Functionality

App details

Otosan is a free Utilities app for iPhone, iPad and iPod touch, developed by HIROSHI SHINKAWA. It requires iOS 26.2 or later, is 102 MB to download and is available in 2 languages. It was first released on March 10, 2026 and last updated on October 29, 2026.

Category: Utilities
Price: Free
Version: 1.6.1
Size: 102 MB
Requires: iOS 26.2 or later
Compatibility: iPhone, iPad, iPod touch
Languages: English, Japanese
Age rating: 4+
Released: March 10, 2026
Last updated: October 29, 2026
Developer: HIROSHI SHINKAWA

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Alternatives to Otosan

Looking for apps like Otosan? Here are 6 similar apps on the App Store. The highest rated is Astro Locator (4.8/5), and 5 of the 6 are free to download.

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