Privacy Policy
Hedwiq (iPhone app) Last updated: October 15, 2026
This policy explains how Hedwiq (“the app”) handles your information. The app is developed independently by Takuro Koyanagi (“the developer”). If this English version differs from the Japanese version, the Japanese version prevails.
Your data
The books, bookmarks, photos, and reading records you add are stored only on your device. They are never sent to the developer’s servers. There is no account, and the app does not collect your name or email address.
Deleting the app also deletes these records from your device. These records are also included in your iPhone backups (iCloud or computer).
Book search
When you search for a book, the words or ISBN you enter are sent to the following external services.
- Rakuten Books (Rakuten Group, Inc.): sent through a relay server operated by the developer.
- Kakao® book search (Kakao Corp.; for Korean books): sent through a relay server operated by the developer.
- NDL Search (National Diet Library, Japan)
- Open Library (Internet Archive)
Only the search words or ISBN are sent. Nothing that identifies you, such as the books or bookmarks you have added, is sent. As part of how internet connections work, your IP address is visible to each service.
Relay server
The relay server does not store your search words or the search results. To prevent abuse, it uses your IP address only to count requests per minute. The IP address is kept only in the server’s memory and is erased within about two minutes. It is not written to any log.
To confirm that requests come from the genuine Hedwiq app, the relay server uses Apple’s App Attest. The information used for this check is not stored and is not used to identify your device or you.
Purchasing Hedwiq Pro
Purchases of the in-app purchase “Hedwiq Pro” are processed by Apple’s App Store. The developer does not receive your payment information, such as card numbers. Whether you have purchased Pro is checked on your device using Apple’s systems and is not sent to the developer’s servers.
Cover images
Cover images are downloaded from Rakuten Books, Kakao®, or Open Library, and are kept on your device for up to 30 days so they appear faster.
Camera and photos
The app uses the camera and your photo library to add bookmarks and book covers. Photos you take or choose are stored only on your device.
Ads and analytics
The app shows no ads and includes no analytics that collect usage data.
Changes
If this policy changes, this page will be updated.
Contact
A reply to every inquiry is not guaranteed.