Privacy Policy

Effective June 25, 2026

This policy describes what ToneYin collects and how it is used. ToneYin — the iOS app and the website at toneyin.ai — is operated by ToneYin LLC (“ToneYin,” “we,” “us”). ToneYin grades your Mandarin pronunciation: you record short prompted phrases, and we analyze the audio to give you per-syllable tone and pronunciation feedback.

Information we collect

  • Audio recordings. When you tap record, we capture your microphone audio of the prompted phrase. The microphone is only active while you are recording. Recordings are uploaded to our servers for grading and stored with your account (in the app) or your practice session (on the website).
  • Account information. You sign in with Sign in with Apple, Google, or an email address and password. Apple and Google share your name and email address with us (with Sign in with Apple you can choose Hide My Email to share a private relay address instead); if you sign up with email, we store the email address you provide. We also assign your account a random user ID.
  • Profile and preferences. To personalize lessons, we store details you provide or choose during onboarding and in settings: a display name, your native language, time zone, self-rated proficiency, why you’re learning, your simplified/traditional script preference, a daily practice goal, and an optional daily reminder time. You may also upload an optional profile photo; we strip location and other embedded metadata from photos before storing them.
  • Learning activity. Your graded attempts, scores, streaks, and lesson progress are stored with your account so the app can show your history and progress.
  • Feedback.If you send feedback through the in-app form or by emailing us, we receive your message along with your app version and platform, and — if you’re signed in — your account, so we can follow up.
  • Website demo information. The toneyin.ai demo asks for optional self-reported details (such as your name, native language, and other languages you speak) to label your recordings, and an optional email address if you want product updates.
  • Usage analytics. We collect basic product events (for example: lesson started, recording graded, lesson completed) along with your user ID and device platform, so we can understand how ToneYin is used. Analytics never include your audio.
  • Crash reports. If the app crashes or hits an error, a diagnostic report (device model, OS version, and technical details of the failure) is sent to us so we can fix it.

How we use your information

  • To grade your pronunciation and show you feedback.
  • To keep your practice history, streaks, and progress.
  • To personalize your lessons and, if you turn them on, send the daily practice reminders you schedule.
  • To improve ToneYin’s pronunciation-grading models. Recordings may be reviewed, labeled, and retained for research and development, as described in the consent notice shown before you record.
  • To respond to your feedback and support requests.
  • To diagnose crashes and fix bugs.
  • To send you product updates, only if you opted in with your email.

What we don't do

  • We do not sell your personal information.
  • We do not show ads or share your data with advertisers.
  • We do not collect your location, contacts, or device advertising identifiers.
  • We do not use your recordings for anything beyond providing and improving ToneYin.

Service providers

ToneYin runs on third-party infrastructure that processes data on our behalf: Supabase (authentication, database, and recording storage), Cloudflare (recording storage for the website demo), Modal (audio analysis), Fly.io (API hosting), Vercel (website hosting), PostHog (analytics), and Sentry (crash reporting). Signing in uses Apple (Sign in with Apple) and Google (Google sign-in), and emails you send us are handled through Google Workspace. Each provider receives only the data needed for its function.

Retention and deletion

Account information, profile details, and learning activity are kept while your account is active. Recordings may be retained for model research and development. In the app, you can delete your account at any time from Settings → Delete Account; this immediately and permanently removes your account, recordings, and associated learning data. You can also email us at hello@toneyin.ai to request deletion, and we will delete your data within 30 days. Feedback you’ve submitted may be kept in de-identified form (with your account link removed) to help us improve the product.

Children

ToneYin is not directed at children under 13, and we do not knowingly collect personal information from them. If you believe a child has provided us personal information, contact us and we will delete it.

Changes to this policy

If we make material changes to this policy, we will update this page and revise the effective date above.

Contact

Questions about this policy or your data: hello@toneyin.ai.