Effective date: July 4, 2026
This Privacy Policy applies to the language-learning apps and websites operated by ai-speeds — including Mando (Learn Chinese), Kototabi ことたび (Learn Japanese) and Wordwing (Learn English) — on the web, iOS and Android (the "Apps").
Learning progress (words learned, review schedule, quiz mistakes, streaks, settings such as language and theme) is saved only in your device's local storage. It never leaves your device, and deleting the App deletes this data.
Purchases in the native Apps are processed by Apple App Store or Google Play, and managed through RevenueCat, our subscription-management provider. For this purpose, an anonymous random app user ID, device type and purchase history are processed to validate and restore your purchases. This data is not used for advertising or tracking, and is not linked to your identity. Payment details (card numbers, billing address) are handled entirely by Apple or Google and never reach us.
If you enable daily study reminders, notifications are scheduled locally on your device. No notification data is sent to any server.
The Apps load static content (word audio, illustrations, grammar data) from our servers. These are ordinary web requests; standard server logs (IP address, timestamp, requested file) may be retained briefly for security and operations, and are not used to profile users.
The Apps contain no third-party analytics SDKs, no advertising SDKs and no cross-app tracking.
The Apps do not collect personal information from anyone, including children.
If this policy changes, the updated version will be posted at this URL with a new effective date.
Questions? Email tangzy09@gmail.com.