Hibi has no account server and no analytics. What you study never leaves your device. One thing does leave: the app talks to a subscription service to find out whether you have paid. This page explains exactly what that means, because a vague privacy policy is worse than none.
What stays on your device
Your learning progress. Every character you have seen, every review, your streak, and your schedule live in a database file inside the app’s private container on your iPhone or iPad. It is shared with the Hibi widget through an Apple app group, which is a folder only Hibi and its widget can read.
Your onboarding answers. How you heard about Hibi, your level, your pace, and which scripts you chose are stored on the device so the app can build your plan and the widget can show the right character.
Your Sign in with Apple identifier. When you sign in, Apple gives the app a stable identifier for you. Hibi hashes it with SHA-256 and stores only the hash, in the device keychain, so that reopening the app skips onboarding. The original identifier is not kept. If you choose to share your name or email with the app, those stay in the keychain on the device too. They are never sent anywhere, and Hibi does not email you.
None of this is uploaded. There is no Hibi account server to upload it to. If you have iCloud Keychain or device backups enabled, Apple’s own backup rules apply, and those are covered by Apple’s privacy policy, not this one.
What leaves your device
Hibi uses RevenueCat to check your subscription and to fetch the layout of the subscription screen. RevenueCat is a subscription infrastructure company based in the United States. It is the only service the app contacts, and it is contacted only about paying, never about studying.
What Hibi sends it:
- An anonymous identifier. RevenueCat generates a random ID for your install. Hibi never gives it your name, your email, your Apple ID, or the hashed Sign in with Apple identifier described above. It is not connected to who you are, and Hibi cannot connect it either.
- Purchase information. When you subscribe, restore, or renew, the App Store transaction goes to RevenueCat so it can verify the receipt with Apple and tell the app whether the widget should unlock. This is which plan and when, not how you paid.
- Basic technical context that comes with any network request, such as your country, the app version, and the operating system version.
What Hibi never sends it: which characters you have learned, your streak, your review history, your onboarding answers, or anything you typed.
RevenueCat’s own privacy policy is at revenuecat.com/privacy.
Your payment details never touch the app or RevenueCat. Payment is handled entirely by Apple.
Tracking
Hibi does not track you. There is no advertising SDK, no attribution tool, and no analytics service in the app. Hibi does not use the Advertising Identifier, does not share data with data brokers, and does not collect data linked to your identity for advertising or measurement. You will never see an App Tracking Transparency prompt from Hibi, because there is nothing to ask about.
Children
Hibi is rated 4+ and contains no objectionable content, no chat, no user-generated content, and no advertising. The only data that leaves the device is the anonymous subscription information described above, and that is the same for every user regardless of age.
Third-party components
Besides RevenueCat, Hibi is built with two open source libraries that run entirely on the device and send nothing anywhere: GRDB (MIT), the local SQLite layer, and swift-fsrs (MIT), the spaced repetition scheduler.
Learning content is derived from open data sets: JMdict and KANJIDIC2 (Electronic Dictionary Research and Development Group, Creative Commons), KanjiVG (CC BY-SA 3.0), and Tatoeba (CC BY 2.0). These are compiled into the app at build time. The app does not contact them at runtime.
Deleting your data
Delete the app. Everything on the device goes with it: the database, the app group folder, and the keychain entry. You can also revoke Hibi’s access to your Apple ID at any time in Settings, under your name, then Sign in with Apple.
For the subscription record held by RevenueCat, email hibiteam.app@gmail.com and we will have it deleted. Because the identifier is anonymous, tell us roughly when you subscribed and which plan, so we can find it. Deleting that record does not cancel your subscription; cancel that in Settings, under your Apple Account, then Subscriptions.
Changes
If this policy changes, the date beside the title changes with it. If a future version of Hibi ever collects anything beyond what is listed here, that will be stated on this page in plain language before the version ships.