Privacy Policy

Effective November 7, 2026

The short version

Your recordings and your voiceprint stay on your devices. Everything Twicy records and learns stays on your iPhone and Apple Watch. To write your English, Twicy sends sentence text, and nothing else, to Twicy's server, which passes it to an AI model provider and does not keep it. To apply daily limits, the server keeps that day's usage counts by a random install ID and IP address, or for Pro by your App Store transaction ID, and resets them every day. There is no Twicy account, no analytics, no advertising, and no tracking, and we never sell data.

Audio

• While listening is on, your Apple Watch records audio and keeps only the parts where someone is speaking.
• Recordings are sent from your Apple Watch to your paired iPhone directly with Apple's WatchConnectivity. They do not go through iCloud or any Twicy server. After a recording reaches your iPhone, it is removed from the watch.
• Recordings are stored in Twicy's private storage on your iPhone.

Speech recognition

• Your recordings are transcribed on your iPhone using Apple's on-device speech recognition. The first time you use a language, iOS may download that language's speech model from Apple.
• When you practice, Twicy listens to the English you speak. By default this also runs on your iPhone only (Settings → On-device recognition only). If you turn that setting off, iOS may use Apple's speech recognition service for practice, under Apple's privacy policy.

Voice ID

If you set up Voice ID, Twicy builds a voiceprint from a short sample of your voice, computed on your iPhone with an on-device model. It is stored only on your iPhone and is used to keep sentences you said and drop sentences other people said. Sentences recognized as someone else's are not saved.

Writing your English

• To turn what you said into English, Twicy sends sentence text only (never audio, never your voiceprint) from your iPhone over HTTPS to Twicy's server in Seoul, South Korea.
• The server passes the text to Twicy's AI model provider, DeepSeek, through DeepSeek's API (DeepSeek's servers are in China), and returns the result to your iPhone. DeepSeek processes the text under its own API terms and privacy policy.
• Twicy's server does not store or log sentence text.

Daily limits

Free and Pro each include a daily amount of English. To apply these limits, Twicy's server counts how much text it has processed that day:

• for free use, per install ID, a random ID the app creates when it's installed, not linked to your name, email, or Apple Account, and per IP address;
• for Twicy Pro, per transaction ID of your App Store subscription or purchase.

These IDs and counts are reset every day at 00:00 UTC and are not kept any longer.

Purchases

Subscriptions and purchases are handled by Apple. To unlock Pro, the app sends Apple's signed record of your transaction to Twicy's server, which verifies it with Apple's certificates. Twicy never sees your payment details, name, or email. You manage or cancel a subscription in iPhone Settings › Apple Account › Subscriptions.

Your sentences and progress

Your sentences, cards, and practice history are stored only on your iPhone. Settings are stored on your device. Nothing is synced to us.

Deleting your data

Deleting Twicy from your iPhone and Apple Watch deletes everything it stored on them, including recordings, sentences, practice history, your voiceprint, and the install ID. Usage counts on the server are gone at the next daily reset. Deleting the app does not cancel a subscription; cancel it in iPhone Settings › Apple Account › Subscriptions.

Children

Twicy is not directed at children under 13 and does not knowingly collect personal information from children.

Changes

If this policy changes, the new version will be posted on this page with a new effective date.

Contact

Questions: kyriecai.me@gmail.com