Privacy policy

Effective 2 September 2026 · Headword for iPhone and headwordapp.com

Headword has no accounts and no server of its own. What you do in the app stays on your iPhone. The one exception is buying Headword Plus, which involves Apple and a payment service called RevenueCat. This page says exactly what that means.

Who is responsible

Headword is made and published by Menyin Chang, an individual developer. For anything about this policy or your data, write to support@headwordapp.com.

What stays on your phone

Everything you create or that the app records about your learning is stored in a database inside the app on your iPhone:

• the words you save and the collections you put them in;
• your review schedule, drill answers and streak;
• the sentences you write in the drill;
• your settings — notification times, words per day and their hours;
• a local record of a few milestones (finishing onboarding, adding a widget, seeing the Plus offer) that the app keeps to decide what to show you next.

None of this is sent to us. We have no way to read it. Deleting the app deletes all of it.

What we do not do

• No account, no sign-in, no email address or name collected.
• No analytics service and no usage data uploaded anywhere.
• No advertising, no ad identifiers (IDFA), and no cross-app tracking — the app never shows Apple's tracking prompt because there is nothing to ask permission for.
• No crash-reporting service.
• No location, contacts, microphone or camera access.

Buying Headword Plus

Purchases are made through Apple's App Store with your Apple Account. Apple handles payment; the app never sees your card or your Apple Account details. Apple's handling of that information is covered by Apple's privacy policy.

To confirm a purchase and keep Plus unlocked on your devices, the app uses RevenueCat (RevenueCat, Inc., United States). When you open the Plus offer, buy, or restore a purchase, RevenueCat receives the purchase receipt from Apple and a random identifier the app generates for your installation. That identifier is not linked to your name, email or any account, and it is not used for advertising or tracking. RevenueCat's own policy is at revenuecat.com/privacy. If you want the purchase records tied to your installation deleted, email us and we will request it from RevenueCat; you keep whatever Plus you bought, since Apple holds the purchase itself.

Builds of the app without RevenueCat configured — such as the ones used in testing — make no network connection at all.

Notifications

Notifications are scheduled on your phone by the app itself. No notification server is involved, and nothing about your notification settings leaves the device.

iCloud, in a future version

Headword is prepared to sync your saved words and collections between your own devices using iCloud. That does not happen yet. When it ships, the sync will use your Apple Account and Apple's iCloud servers under Apple's privacy terms; the data goes to your private iCloud storage, and we will still have no access to it. This page will be updated when that version is released.

Word data

The dictionary content in the app comes from Wiktionary (CC BY-SA 4.0), with example sentences and notes written for Headword. It is shipped inside the app and looked up on your phone; searching or reading a word does not contact any server.

This website

headwordapp.com sets no cookies and loads nothing from third parties — no fonts, no scripts, no analytics. It is hosted on GitHub Pages, whose servers keep ordinary request logs (such as your IP address) under GitHub's privacy statement.

Email

If you write to support@headwordapp.com, we keep your message and address for as long as it takes to help you and to keep a record of the conversation. We do not add you to any list.

Children

Headword is for readers who already work in English. It is not directed at children under 13, and we do not knowingly collect anything from them — which, given the above, would be nothing in any case.

Changes

If this policy changes, the new version will appear here with a new effective date. A change that affects what leaves your phone will also be noted in the app's release notes.