Klassian Privacy Policy

Elkanah (sole proprietor: Kyujin Cho) · Business Registration No. 322-29-01953

Rm B211-11, Glocal Industry-University Cooperation Hall, Dankook University, 152 Jukjeon-ro, Suji-gu, Yongin-si, Gyeonggi-do 16890, Republic of Korea · Contact: support@klassian.com

Effective date: September 22, 2026 · This policy replaces the version dated September 14, 2026.

Klassian is operated by Elkanah (sole proprietor: Kyujin Cho). Elkanah is the data controller for the processing described below.

1. What we collect, why, and on what legal basis

1.1 Account and profile — when you sign in

Sign in with Apple, Sign in with Google, and Kakao sign-in are currently available. Whichever you use, the data we process and our purposes are the same.

Kakao sign-in also sends us a profile picture URL — Kakao's sign-in specification does not let us leave that item out of the request. It is optional: you can decline it on Kakao's consent screen and still sign in, in which case nothing is sent. If it is sent, we store it with your account but never display it anywhere in the app and never use it for any other purpose, and it is deleted when you delete your account.

Your display name is visible to members of groups you belong to, and changing it updates all of them.

1.2 Group collaboration — when you create or join a group

Group name, membership (role, display name), shared events (title, time, notes, venue), polls and votes, one-to-one lesson requests and comments.

• Purpose: providing shared scheduling. Legal basis: contract.
• Visibility: what you write is visible to members of that group (lesson requests and comments: only the two people involved). This is the feature working as designed, not a disclosure to third parties.
• While an invite link is valid, anyone holding it can see one thing before signing in: the group's name.

1.3 Notifications — if you allow them

Push token, platform, app version, language. Legal basis: contract.

Notification titles and bodies — including event titles and comment text you wrote — pass through Apple's push service (APNs), which may retain them for up to 24 hours for delivery. See §5 (International transfers).

1.4 Practice hand-off — while a practice session is running

While you practice, the session's state (score name, composer, elapsed time) passes through our server so your other devices (e.g., iPhone Lock Screen) can display it. It is deleted from the server when the session ends. Legal basis: contract.

1.5 Gaze improvement data — only with your separate consent, pseudonymous

• A pseudonymous install identifier (random UUID). It is not linked to your account or email, and we do not attempt to link it.
• Derived metrics only: calibration error, head and eye angles, distance from the screen, calibration and practice-game samples expressed as screen coordinates, page-turn success/attempts, dwell times, device model, OS version, TrueDepth availability, and gaze-related events (calibration started, page turned, recalibrated, and similar).
• If you also opted into instrument sharing: your instrument family (e.g., strings).
• What is never collected or transmitted: camera footage, photos, face images, individual frames, or any record of where you look while reading a score. All gaze computation happens on the device.
• Purpose: improving the accuracy and reliability of Klassian’s gaze page-turning (calibration, dwell detection, and device-specific tuning). It is not used for any other purpose, is not used to identify anyone, and is not shared with third parties. Legal basis: consent, withdrawable at any time in Settings.
• Declining changes nothing — every feature, including gaze turning, works the same.

1.6 Usage analytics — only with your separate consent

Home screen usage and paywall interactions (paywall shown, plan comparison opened, purchase button tapped) — linked to your account, and deleted with it. It is stored and transmitted separately from gaze data (§1.5), and the two are never combined. Your scores, annotations, and playing are never part of it. Purpose: understanding which features are used and where friction occurs. Legal basis: consent. Declining changes nothing.

1.7 Payments — handled entirely by Apple

Purchases, renewals, and refunds are processed by Apple through the App Store. We never see your payment details, and we do not even store your subscription status on our servers — your device verifies it directly with Apple. If we grant you an access tier ourselves (beta testers, goodwill), only that grant is stored. Legal basis: contract.

1.8 Consent records

What you consented to, when, and in which app version — kept because the law requires us to be able to demonstrate consent (Art. 7(1)). Legal basis: legal obligation (Art. 6(1)(c)).

1.9 Marketing — only with your separate consent

Whether you opted into marketing messages. Declining has no effect on the service. Legal basis: consent.

1.10 Sign-up forms on our website — only if you submit one

• Launch updates: name, email address.
• Beta tester application: name, email address, affiliation, iPad model, whether you wear glasses or lenses, instrument, playing posture, practice frequency, score app you currently use, availability for the test and for an interview.
• Purpose: to send the launch announcement, and to select and contact beta testers.
• Legal basis: consent, given by submitting the form.
• Collected through Google Forms and Google Sheets — see §4 and §5.

This data is not linked to an app account, and is never combined with gaze improvement data (§1.5).

1.11 Score download records — when you download from IMSLP (required)

• The file: IMSLP file number, file name, work title, composer, the copyright/licence notice shown on screen when you downloaded, page count, file size.
• What happened: opening score search, download started / completed / cancelled / failed and when, that you saw IMSLP's notice page, and whether the file landed in My Scores.
• App version and your account identifier.
• Purpose: to respond to legitimate requests from rights holders and IMSLP, to act on breaches of the Terms, and to evidence which notice a score was downloaded under.
• Legal basis: consent — asked once, the first time you tap Download, not at first launch. If you never use the IMSLP feature, nothing here is collected.

Search terms and works you merely browse are not part of this — they fall under §1.6 usage analytics (optional). Downloading requires sign-in; searching, browsing and previews do not. The score file itself is fetched by your device directly from IMSLP and never passes through our servers (§5).

2. What stays on your device and in your own iCloud

The following never reaches our servers. It lives on your iPad and, if iCloud sync is on, in your own iCloud (your Apple account's private storage):

your score PDFs and covers · annotations, stamps, and text notes · your personal calendar including fees and settlement records · practice history · your gaze calibration state · library folders · group cover photos · app preferences (including sleep-alarm settings).

iCloud sync is on by default. Data in transit passes through Apple's servers but is stored in your private iCloud space, which we cannot access. You can turn sync off at any time in Settings → iCloud Sync, or exclude just your scores. Apple's privacy policy governs that storage.

Recordings of your playing never leave the device at all — they are excluded even from iCloud sync.

3. How long we keep things

4. Processors

5. International transfers

Our servers are in the Republic of Korea. The European Commission has decided that Korea provides an adequate level of data protection (Decision of 17 December 2021, reconfirmed July 2026), and the United Kingdom has made the equivalent determination (Data Protection (Adequacy) (Republic of Korea) Regulations 2022). Your data may therefore be processed in Korea without any additional transfer safeguard.

When notifications are delivered, notification content (§1.3) is transferred to Apple Inc. (United States) for the sole purpose of delivery, retained for up to 24 hours. Apple is certified under and/or relies on recognised transfer mechanisms for its services; turning off notifications in iOS Settings stops this transfer entirely.

If you submit a sign-up form on our website (§1.10), the data you enter is transferred to Google LLC (United States), which hosts the form and the response sheet. Google relies on the EU Standard Contractual Clauses and the UK Addendum for such transfers. Not submitting a form avoids the transfer entirely; you can write to support@klassian.com instead.

When you use score search (§1.11), your device connects directly to IMSLP (Petrucci Music Library, Canada · imslp.org). This is not a transfer by us — it is traffic between your device and IMSLP — but you should know about it.

• What IMSLP receives: your device's IP address and the app's identifying request headers (app name, version, our contact address).
• What stays on your device: the flag that you accepted IMSLP's notice and, if you sign in to an IMSLP account, that sign-in cookie — stored only on your device.
• The score file is downloaded by your device from IMSLP directly. It never passes through our servers, and we do not store or redistribute scores.
• IMSLP's handling of your data is governed by IMSLP's own policy (imslp.org).

Social sign-in and App Store payments may likewise involve those providers' servers abroad, under their own privacy policies. iCloud sync (§2) is a service between you and Apple.

6. Sharing

We do not sell personal data, share it for advertising, or disclose it to third parties, except where the law requires or you separately consent. There is no third-party analytics or advertising SDK in the app.

There is one exception:

• Recipient: a rights holder or their representative, or IMSLP (Petrucci Music Library).
• What: the relevant entries from your score download records (§1.11) and your email address.
• When: on a request required by law, or a legitimate request from a rights holder, once we have verified that it is legitimate.
• What we cannot share: the identity behind a deleted account — it no longer exists (§3).

7. Gaze and camera — specific commitments

• The camera is used on the device only, to compute where you are looking. No footage, photo, or face image is ever stored or transmitted anywhere.
• We do not record where you look while reading. The only coordinates that leave the device are discrete calibration and practice-game samples — moments when the app asked you to look at a specific target — and only with your consent (§1.5).
• Gaze data is keyed to a pseudonymous identifier, stored in a separate server environment from account data, and it is our policy never to combine the two.
• For that reason, we cannot locate and delete any one person's gaze data — we cannot tell whose it is (see §8, Art. 11). What you can always do: withdraw consent in Settings, which stops collection instantly and discards anything still queued on the device.

8. Your rights

If you are in the EU/EEA or the UK, you have the right of access, rectification, erasure, restriction, portability, and objection (Art. 15–21 GDPR), and the right to withdraw consent at any time without affecting prior processing (Art. 7(3)). Most of this you can do directly in the app: edit or delete your profile, instrument, events, and scores; toggle each consent in Settings; delete your account in Settings.

• Data export: email support@klassian.com and we will provide your data.
• Account deletion removes your account, profile, group activity, notifications, usage analytics, and consent records from our servers immediately. Four things to know:
  • Groups you own are deleted entirely — including shared events, polls, and comments that other members were using.
  • Nothing on your device or in your iCloud is deleted — remove it yourself if you wish.
  • Pseudonymous gaze data is not deleted, because it is not linked to your account (§7). Under Art. 11 GDPR, where a controller cannot identify the data subject, Articles 15–20 do not apply; we also do not collect extra information just to make identification possible.
  • Score download records remain, anonymised (§3) — your email and everything else that identifies you is erased immediately, and what remains cannot be traced back to you.
• If you leave a group, what you wrote stays with the group, attributed to "a former member".
• You also have the right to lodge a complaint with a supervisory authority — in Korea, the Personal Information Protection Commission (privacy.go.kr); in the EU, your national data protection authority; in the UK, the ICO (ico.org.uk).

We do not use automated decision-making or profiling that produces legal or similarly significant effects (Art. 22).

9. Children

Klassian does not knowingly collect personal data from children under 14 (or the higher age applicable in your country, e.g., 16 where national law requires). Sign-up includes an age confirmation, and accounts cannot be created below the threshold.

10. Security

Encryption in transit (HTTPS) throughout; row-level security so that no query returns data beyond your own or your group's scope; identity data and gaze data kept in separate server projects with separate keys; session tokens in the device Keychain; no server admin keys in the app or repository; consent history stored append-only.

11. Changes

We will announce changes in the app and on the website at least 7 days before they take effect — 30 days for material changes such as new data categories or purposes.