Privacy & usage data
What we collect
Curtain English stores first-party, anonymous usage statistics to understand how the site is used and to improve the reading experience. This works whether or not you are signed in.
- A random visitor ID stored in your browser's
localStorage(not your name or email) - Pages you visit, reading session starts, page completions, and quiz answer outcomes
- UI language preference, referrer URL, and browser user-agent string
- Approximate country and region inferred from your connection (ISO country code only — your IP address is not stored)
- If you sign in, your visitor ID is linked to your account so we can see pre- and post-login activity as one journey
What we do not collect
- Quiz answer text or comprehension question content in analytics events
- Raw IP addresses in our analytics database
- Third-party advertising or cross-site tracking pixels
Contact form
If you use our Contact page, we store the name (optional), email address, subject, and message you submit so we can respond. If you are signed in, we may link the message to your account. We do not use contact messages for advertising.
Authentication cookies
Sign-in is handled by Clerk, which sets its own session cookies. Those are separate from the anonymous visitor ID above and are required only when you choose to log in and save reading progress.
Curtain Reading Chrome extension
The Curtain Reading browser extension is a separate product surface from the Curtain English website. When you use the extension on a web page:
- Visible text on the active tab is measured only inside your browser so the curtain can cover lines you have already read
- Page content is not uploaded to our servers
- We do not sell browsing data or use the extension for advertising
- Preferences such as curtain speed may be stored locally in the extension (
chrome.storage) on your device
The extension requests broad site access so it can run on the article page you choose to start. You control when the curtain runs (Start / Cancel from the toolbar or on-page controls).
Curtain English iOS app
The Curtain English mobile app (App Store) uses the same account and backend as the website. When you use the app:
- Sign-in is handled by Clerk (Sign in with Apple, Google, or email). Session tokens are stored on your device using secure storage
- Reading progress, vocabulary, and quiz outcomes are saved to our servers when you are signed in, so you can resume on other devices
- We collect the same first-party usage statistics described above (visitor/session events, UI language, approximate country) when the app calls our API
- We do not sell personal data or use the app for third-party advertising
- Library Pass subscriptions, when offered, are processed according to the payment method shown in the app (web checkout or in-app purchase, depending on platform and release)
The app does not read arbitrary websites; it only loads books from the Curtain English library. The Curtain Reading Chrome extension is a separate product.
Age suitability (iOS app)
Curtain English is an education app for people learning English by reading classic literature from our library. It is not designed for children under 13 as a standalone product, and it is not listed in Apple's Kids Category.
- A free account is required to save reading progress, vocabulary, and quiz results across devices (Sign in with Apple, Google, or email)
- The app loads books from the Curtain English library only — not arbitrary websites
- There is no social feed, messaging, user-generated content, gambling, or third-party advertising
- Books are public-domain classics, often in their original, unabridged form. Depending on the title, mature themes (for example war, alcohol, or romance) may appear in a literary context
Parents and guardians should help younger readers choose appropriate titles. The age rating shown on the App Store reflects our responses to Apple's content questionnaire and may vary by country or region.
Questions? Use our Contact page.