Effective date: August 23, 2026

한국어 개인정보 처리방침

Hitosuji turns a photo of a marked book page into a card you can share. It is made by weuse, a sole proprietorship in the Republic of Korea. Your photos and the sentences read from them never leave your phone. The only thing that reaches us is the text you type when you look up a book.

What stays on your device

Reading the text, finding the highlighter marks, cutting out your handwriting, drawing the card, and rendering the video all happen on the phone using Apple's Vision framework. None of it is uploaded.

The one thing that leaves your device: a book search

When you look up a book, the words you type and a language code go to our small proxy at Cloudflare, which asks a book database and returns the results. No name, no email, no account, no advertising identifier travels with it.

We do not store what you searched for. Results are cached for 24 hours so a repeated search is fast, then they disappear. We keep no access logs.

Who sees the search

WhoWhat they doWhere
Cloudflare, Inc.Runs the proxyUnited States and global edge
Kakao Corp.Korean book dataRepublic of Korea
Google LLCInternational book dataUnited States
Rakuten Group, Inc.Japanese book dataJapan
Internet Archive (Open Library)Book dataUnited States

Each of them can see the internet address (IP) your request arrives from, as any web service can. We never receive it.

Apple handles subscription payments. We never see your card or your payment details, only whether a subscription is active.

What we do not do

No account. No advertising. No analytics or crash reporting SDK. No tracking across apps or websites. Nothing is sold or shared with data brokers.

Photos and camera

The app asks for the camera to photograph a page, for your photo library to pick a page you already shot, and for permission to save a finished card or video back to your library. It reads only the photo you choose and writes only what you ask it to save.

Your rights

If you are in the EU or the UK, the GDPR gives you the right to access, correct, erase, restrict, and object to processing, to data portability, and to complain to your supervisory authority. Elsewhere, comparable local rights apply. Since we hold nothing tied to you, most requests are answered by telling you exactly that, and everything on your phone is yours to delete.

Our legal basis for the book search is legitimate interest: sending your query to a book database is the only way to answer it, and we keep nothing afterwards.

Write to weuse.support@gmail.com and we reply within 30 days, free of charge.

Children

The app asks no age and creates no account. The only thing that reaches us is a book search, so no child's personal information accumulates here.

What deleting the app removes

Everything. Photos, sentences, cards, videos, your shelf, and your settings live on the phone, so deleting the app deletes them. Cards you already saved to your photo library stay there, because those are yours. A subscription is managed by Apple and is cancelled in your Apple account, not here.

Changes

If this policy changes, the effective date at the top changes with it and the change is listed below.

Contact

weuse, a sole proprietorship in the Republic of Korea. Privacy matters reach the owner directly.

weuse.support@gmail.com

Governing law

The laws of the Republic of Korea, where weuse is established.

Change log

DateWhat changed
2026-08-23First published