Last updated: 30 October 2026
PracticeTwin (practicetwin.app) is run by Doug Shum in Brisbane, Queensland, Australia, ABN 68 992 572 301. Personal information is handled under the Australian Privacy Principles. Questions go to privacy@practicetwin.app.
老師開戶口要 email（或 Google 登入）。我哋儲你嘅名、教咩、你嘅語氣設定、學生資料同你改過嘅回饋。
學生冇戶口——條專屬 link 入面嗰串字就係佢嘅身分。所以條 link 唔好公開貼。我哋儲嘅係：名、樂器、每日自評、你寫嘅任務、（可選）家長 email、（可選）30–60 秒錄音。
錄音只有你（老師）同埋嗰個學生自己聽得到；交咗之後邊個都改唔到、刪唔到。
AI：出任務同回饋草稿會將任務內容、自評分數同學生留言送去 Anthropic（Claude API）。錄音檔從來唔會送去任何 AI。Anthropic 唔會攞嚟訓練模型。
付款全程喺 Stripe 度，我哋見唔到你張卡。冇廣告、冇追蹤 cookie、唔賣數據。
想刪走全部嘢：email 我哋，30 日內做完。
| What | Why |
|---|---|
| Email address (or Google account) | Signing in; sending you the daily digest and a copy of each parent report |
| Your name and instrument | Shown to students and on the parent report |
| Your "tone" description | So drafted replies sound like you |
| Optional monthly fee amount | Shown on the parent report next to practice minutes, if you fill it in |
| Time zone | So the weekly report goes out at 18:00 your Sunday |
| Every draft you edited, with your edit | Kept as your own rubric, so the drafting gets closer to your voice. It is yours and is never shown to another teacher. |
| Subscription state (plan, Stripe customer id, renewal date) | Billing. We never see or store card numbers. |
A student has no account. Their identity is the 24-character token inside the personal link their teacher gives them. That link is a key: anyone holding it can see that one student's page, so it should not be posted publicly.
| What | Why |
|---|---|
| Name and instrument (entered by the teacher) | Shown on their page and the report |
| The weekly goal and six daily tasks | The practice plan |
| Daily self-rating (1–5), optional note | What the teacher reads and replies to |
| Optional 30–60 second audio recording | So the teacher can hear the practice |
| Optional parent email address | Weekly report and reminder fallback. Only if the teacher enters one. |
| Optional reminder time and push subscription | Daily reminder, only if the student turns it on |
We ask students for no email address, no phone number, no date of birth and no location.
A recording is readable by the teacher who owns that student, and by that student. It is create-only: once submitted, it cannot be overwritten or deleted by a student, so what the teacher hears is what was sent. Recordings are capped at 10 MB and are stored in Google Cloud Storage. Recordings are never sent to any AI service.
PracticeTwin uses the Claude API from Anthropic for three things: splitting a teacher's weekly goal into six daily tasks, drafting a reply to a submission, and writing the paragraph at the top of the weekly parent report.
What is sent to Anthropic:
What is not sent: audio files, email addresses, parent details, payment details, and anything belonging to another teacher.
Anthropic processes these as a service provider and does not use them to train models. Every draft is checked or length-limited by us before storage, and a student sees nothing the teacher has not approved (unless the teacher has turned on auto-approve for that student, which is off by default).
If the teacher entered a parent email address, we send that parent one email on Sunday evening with: days practised that week, the number of days the student promised themselves, the average self-rating, the current streak, the planned practice minutes completed, the teacher's most recent approved reply, and — if the teacher filled it in — the monthly fee. The teacher is copied on it.
The same information is drawn as a picture and stored at a public, unguessable URL so it can be forwarded. Anyone with that URL can see that one card. It contains the student's first name and the figures above; it contains no contact details and no recording.
| Service | What they see |
|---|---|
| Google Firebase (Firestore, Storage, Authentication, Cloud Functions) — hosted in the United States | Everything above. They are our infrastructure. |
| Anthropic (Claude API) | Only the text listed in section 3. |
| Resend | Email addresses and the content of the emails we send. |
| Stripe | Teacher billing. Card details go directly to Stripe and never reach us. |
We do not sell data, we do not run advertising, and we do not share anything with anyone not listed above, except where the law requires it.
We use no advertising or analytics cookies. Firebase Authentication stores a sign-in session
in the teacher's browser. The landing page remembers your language choice in
localStorage. That is all.
Student records live as long as the teacher keeps the account. A teacher may delete a student, which removes their page, their submissions and their recordings. Stripe event records used to stop duplicate billing updates are discarded after 60 days.
You can ask for a copy of your data, a correction, or deletion, by emailing privacy@practicetwin.app. We act within 30 days. A parent may ask for their child's record to be deleted; we will confirm with the teacher who owns that record and then remove it.
If you are unhappy with how we handled a privacy matter, you may complain to the Office of the Australian Information Commissioner (oaic.gov.au).
PracticeTwin is bought by teachers, not by children, and a student needs no account. The teacher is responsible for having the parent's permission before adding a student under 13 and before entering a parent's email address.
If this policy changes materially we will email account holders. The date at the top is always the current version.