Privacy Policy
Effective date: July 25, 2026
This policy explains what information SurfEnglish ("we", "us") collects when you use the SurfEnglish iOS app and the surfenglish.app website, and how we use it. The short version: your learning data lives on your device, we show no ads, we do not track you across apps, and we collect only what we need to run the service.
What stays on your device
Most of what you do in SurfEnglish is stored locally on your iPhone and is never uploaded:
- Your learning database — translated sentences, looked-up words, language chunks, game statistics and review schedules.
- Articles fetched from custom RSS feeds you add, and cached feed content.
- The on-device AI voice (Kokoro) generates all audio locally — text you listen to with it never leaves your phone. The optional local translation engine (Apple's Translation framework) also runs entirely on-device.
You can clear cached content at any time in Settings → Storage inside the app. Deleting the app removes all local data.
Information we collect
Account (optional)
SurfEnglish works without an account. If you choose to Sign in with Apple, we receive an identity token from Apple and store only a one-way hash of your Apple account identifier to recognize you. We do not store your name or email address. Session tokens are kept in the iOS Keychain on your device.
Synced learning data (only when signed in)
Signing in enables sync of: your followed topics, custom RSS feed definitions (the feed URLs, not the articles), saved vocabulary words and language chunks (including the sentence they came from), and reading interactions (which articles you opened or saved, and reading progress). This data is stored on our servers so it can follow you across devices, and is associated with your account.
Text you actively translate or look up
When you translate a sentence, look up a word, extract chunks, or use the cloud voice, the selected text (with some surrounding context) is sent to our translation service — which uses established cloud translation providers such as Microsoft and Google — to produce the result. We use it to fulfill your request and to cache results; we do not build a profile of your reading from it.
Purchases
SurfEnglish Plus subscriptions are processed entirely by Apple. We never see your payment details. The app verifies your entitlement with Apple and, if you are signed in, associates the subscription with your account so it can follow your Apple ID.
Usage analytics
We use Firebase Analytics (Google) to understand which features are used — events like "article opened", "translation used", "game started", plus app version, device model, language and region. We deliberately exclude content: the text of articles you read, words you look up and translations are never sent to analytics, and web addresses are reduced to the site name. If you sign in, analytics is linked to your account identifier so we can understand usage across devices. Apple also reports anonymized purchase events to Firebase.
What we don't do
- No ads, and no advertising SDKs.
- No tracking across other companies' apps or websites, and no use of the Apple advertising identifier (IDFA).
- We never sell your personal information.
Third-party services
- Apple — Sign in with Apple, StoreKit purchases, and optional on-device translation language packs.
- Google Firebase Analytics — usage analytics as described above.
- Google favicon service — the app loads small site icons for news sources from Google, which reveals the source's domain name (not the article) to Google.
- Websites you visit — the built-in browser loads the pages you choose to open, like any browser; those sites see your visit under their own policies.
Data retention and deletion
- Local data — under your control; clear it in Settings → Storage or by deleting the app.
- Account and synced data — kept while your account is active. To delete your account and all synced data, email chijinlong@gmail.com with the request "delete my SurfEnglish account"; we will complete the deletion within 30 days.
- Analytics — retained according to Firebase Analytics' standard retention settings.
Security
All network communication uses HTTPS. Session credentials are stored in the iOS Keychain. Custom RSS feeds are fetched over HTTPS only.
Children
SurfEnglish is not directed at children under 13, and we do not knowingly collect personal information from children.
Changes to this policy
If we change this policy, we will update this page and the effective date above. Material changes will be highlighted in the app.
Contact
Questions about privacy? Email chijinlong@gmail.com.