Privacy policy

Effective 17 September 2026 · Headword for iPhone and headwordapp.com

Headword has no server of its own and needs no account. 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, and what the phone heard when you said a word aloud;
• your profile — the name you type (or accept from Apple's sign-in sheet), and if you set them, your gender, age band and English level;
• the word games you play and their results;
• 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 of ours, and no email address collected. Sign in with Apple is optional and explained below; your name never leaves your phone.
• 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 or camera access. The microphone is used only for the optional "Say it" practice step, only after you allow it, and only on your phone: recognition runs on the device, and no audio is stored or sent anywhere.

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.

Sign in with Apple (optional)

You can sign in with Apple from your Profile. It is never required: every screen and every purchase works without it. Signing in does not create an account with us — we have no server to keep one on. It does one thing: the random installation identifier RevenueCat holds for your purchases is replaced by the identifier Apple issues for you, so Headword Plus and your profile settings follow you to a reinstall or to a second iPhone.

Once you have signed in, three things from your Profile are sent to RevenueCat and stored against that identifier: your gender, your age band and your English level, if you have set them. We use them only to see, in aggregate, who Headword's readers are. They are not used for advertising and are never shared further. Your name is not sent: whether you type it or accept it from Apple's sign-in sheet, it stays on your phone.

Signing out removes the link on your phone and starts a new random identifier; your purchases can be restored at any time. Delete account, under Sign out in your Profile, goes further and is immediate: it removes your gender, age band and English level from RevenueCat, deletes your profile details and your Apple sign-in from your phone, and detaches the app from the record held under your Apple identifier. Your saved words and practice history stay on your phone, and a subscription is not cancelled — you manage that in Settings, under your Apple Account. What remains at RevenueCat is that identifier with your purchase receipts and nothing else. To have RevenueCat delete that record too held under your Apple identifier, write to support@headwordapp.com. You can also stop Headword using your Apple ID at any time from your iPhone's Settings → Apple Account → Sign in with Apple.

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.