Develop perfect and relative pitch with this ear training app focused on just intonation. Learn to identify and match harmonic intervals by ear, moving beyond equal temperament. Ideal for musicians and singers seeking precise intonation.






47+ iOS apps & games curated and reviewed
Out of 47+ toshihiko arai apps on iOS, 20 are free and the rest sit in the paid tier. This page sorts them so you can compare both sides before you commit.






Develop perfect and relative pitch with this ear training app focused on just intonation. Learn to identify and match harmonic intervals by ear, moving beyond equal temperament. Ideal for musicians and singers seeking precise intonation.



Practice your Japanese flick input and typing speed with this game. Master character input, compete in global rankings, and even use it for English, Chinese, and Korean language learning. Aim for level 30 and share your progress.




Enhance your live streaming experience with a comprehensive comment viewer. Customize comment colors, enable text-to-speech, and automatically fetch comments from upcoming broadcasts. Post comments directly and integrate with TV commentary.




This app is an acoustic experiment tool that displays waveforms like an oscilloscope and features various sound modulation options, including a low-pass filter, tremolo, and vibrato. It's useful for measuring speaker and amplifier performance, sound experimentation, and synthesis, with additional features available through in-app purchases.




Experience a Japanese Yaoi visual novel set in the Edo era. Explore forbidden relationships and twisted love stories with voiced characters. Navigate complex emotions and dark desires.


Access real-time foreign exchange (FX) market information with visual trend analysis. Track major currency pairs and customize your view to focus on essential trading data. Ideal for travelers, business trips, and active traders.


This app provides real-time earthquake information, including location, magnitude, and intensity. It also features a "Now Here!" function to share your current location with contacts via SNS. The app displays data from the National Research Institute for Earth Science and Disaster Resilience.


Access and search for the latest job listings from the official government employment support service. Save your favorite positions, store search criteria, and receive notifications for application deadlines. Ideal for job seekers looking for a convenient way to find employment opportunities.


Get real-time rain cloud information for the entire country, with forecasts up to 13 hours ahead. Easily check daily weather, precipitation intensity, and severe weather alerts. Access detailed meteorological data and radar imagery for informed planning.




Access real-time river conditions and weather forecasts across Japan. View over 10,000 river locations on a map and check detailed precipitation, temperature, and snow data. Stay informed about weather changes to prepare for heavy rain and other natural events.




Access real-time bus schedules and operational status for Keio Bus routes. This user-friendly app provides information on approximately 5,400 bus stops, allowing you to easily check departure times and current conditions for your regular routes.









