Musizz

Musizz · Privacy

Privacy Policy

Last updated: 29 September 2026

Current version: we use PostHog for usage metrics and Sentry for technical error reports, as described in this policy. Purchases on iPhone or iPad are processed by the App Store, with RevenueCat verifying Premium access. Browser purchases use RevenueCat Billing, with Stripe processing payments. Contact: [email protected]. Controller: DotRex Studio.

1. Who we are

Musizz is a music-practice app (Expo; web today, iOS/iPadOS App Store in preparation). The controller of personal data is DotRex Studio.

  • Email: [email protected]
  • Repository: https://github.com/diiegopereira/chord-rush
  • iOS bundle id: app.musizz

2. Summary

The app uses the microphone to detect notes and chords on-device. You must sign in to access the app area. The credit balance is stored on the server and follows the same account across devices. We do not record practice audio or upload the sound to a server we operate.

Purchases and subscriptions on iPhone or iPad use RevenueCat to check plan status. Browser purchases use RevenueCat Billing, with payments processed by Stripe. We use PostHog for usage metrics and approximate location inferred from IP, and Sentry for technical error reports and sampled performance data. These services do not receive audio; we do not sell data or use PostHog cookies for anonymous web visitors. The login screen displays only methods the authentication service reports as available.

3. Microphone (pitch detection)

We request microphone access only when you start a session (Rush, arcade, tuner and other modes). The signal is analysed in real time on the device (Fret Rush YIN detector) to recognise a note or chord.

  • We do not write the practice session to an audio file.
  • We do not store the audio on the device or in the cloud.
  • We do not send the audio to servers operated by us or by third parties.
  • You can revoke the permission in system settings. Without the microphone, modes that depend on it will not work (on web, ?demo=1 simulates hits and misses).

4. Data on the device

High scores are stored locally on the device — on the web, in localStorage under the prefix chord-rush-best. Interface preferences may also stay on-device. These values are not synced to a server today.

5. Purchases and subscriptions — Apple, RevenueCat and Stripe

Purchases on iPhone or iPad are processed by Apple App Store; RevenueCat processes transaction and subscription-status information to verify Premium access. Browser purchases use RevenueCat Billing, which uses Stripe to process payments. Musizz does not receive your full card number, and RevenueCat states it does not directly handle or store full card details in this flow. Apple, RevenueCat, and Stripe may process data needed for the purchase, such as identifiers, transaction information, and subscription status. Price, billing period, renewal terms, and benefits are shown before confirmation. No free trial is offered at launch.

6. Analytics and errors — PostHog and Sentry

  • PostHog records page/screen views and usage events such as session starts and finishes, paywall views, purchases, and completed surveys. Events include platform, language, app version, and plan; after sign-in, they are linked to the account UUID. On iOS, the SDK also uses a technical device identifier. PostHog estimates approximate location from the connection IP and discards the raw IP before storing the event; we do not collect GPS. Anonymous web visitors do not receive PostHog cookies. We do not use click autocapture or session recording (Session Replay).
  • Sentry receives technical error reports and sampled performance data, which may include device/browser type, app version, stack trace, and account UUID when you are signed in. In addition to crash and performance data, Sentry also collects other technical diagnostic data to support app functionality. Native crash reports may also include a technical app installation identifier, including while you are signed out. We do not send email to Sentry, and the project is configured not to store IP addresses. Neither service receives practice audio.
  • We process this data under legitimate interests to understand usage, detect failures, and improve the product. We do not sell the data or use it for advertising tracking. To request deletion or exercise rights related to this data, contact [email protected].

7. Account and login

You must sign in with an account to access the app area. The authentication service processes the account identifier, email, and sign-in method to maintain the session. This release is configured with Apple and Google sign-in, but the methods shown depend on authentication service availability. When enabled, email methods may send a one-time code or sign-in link. The session is stored in iOS/Android SecureStore or web localStorage. The server links credits and credit transactions to the account UUID; daily credits reset at 00:00 UTC. When credits run out, you may answer short, optional surveys about musical profile, goals, how you found Musizz, and your experience. Answers support product and marketing research, remain linked to the account so you can resume a survey, and earn +5 credits only after server confirmation, at most once per day and once per survey version. There are no right answers; personal questions can be skipped with “Prefer not to answer” without reducing the reward. Answers are not required to use the app with Premium or return after the reset. The standard marketing export is aggregated or pseudonymized and excludes email addresses. Deleting your account from the Account screen removes the authentication record, ends active sessions, and removes the account’s credit balance, credit transactions, survey drafts, and answers. Account deletion also starts a tracked process to remove associated telemetry from PostHog and Sentry. The PostHog request stays pending until there is evidence of completion; request acceptance or the absence of a profile does not prove deletion. Sentry removal always requires manual review because deleting an issue may affect other people’s data. Our operational target is to resolve or escalate the case within 30 days; this is an internal target, not a provider SLA or guarantee. Cases still pending on D30 are escalated, with retries and review continuing through D90. The technical identifiers needed for retries and late-event audits are kept encrypted for up to 90 days, including after an initial confirmation. At D90, we delete those identifiers; if deletion is still unverified, only an operational record under a random reference with unresolved status remains. The app reports that the server recorded the request; this does not confirm completion by a provider. Retention of the notice address, the Sign in with Apple refresh token, and backups is described in the Retention section. If the telemetry request is not confirmed, contact the email in this policy. If deletion asks you to revoke Sign in with Apple manually, follow the instructions shown. Deleting your account does not cancel App Store subscriptions purchased on iPhone or iPad; manage them in the Apple account used for purchase. Browser subscriptions are canceled when RevenueCat processes deletion of the customer record. Until then, you can cancel through the link in RevenueCat Billing emails. Game scores and progress remain local and are not synced to a server.

8. Web technical data

The operating system, server, or CDN may log IP address, user-agent, and access time for operation, security, and diagnostics. PostHog uses the connection IP to infer approximate location (such as country, region, or city); we do not request precise location or GPS access.

9. Legal bases (LGPD)

Where Brazil’s General Data Protection Law (LGPD) applies, the intended bases are:

  • Consent: microphone access when required by applicable law.
  • Performance of a contract: providing the app and, if offered, a paid subscription.
  • Legitimate interests: understanding app usage, improving the product, detecting errors, and maintaining security and technical operation.
  • Legal or regulatory obligation: complying with duties imposed by applicable law, such as applicable tax obligations.

Usage analytics and technical error and performance reports are processed under legitimate interests to improve and maintain the app. You may exercise your rights, including requesting deletion of this data, through the contact email.

10. Sharing

We do not sell your data. We may share information with:

  • Apple (App Store and system permissions on iPhone or iPad) and operating-system providers for required permissions.
  • The authentication service, Google or Apple when you choose either provider to sign in, and the email delivery service when email methods are enabled.
  • The Musizz service that syncs credit balances and stores survey drafts and answers.
  • Apple App Store and RevenueCat for iPhone or iPad purchases; RevenueCat Billing and Stripe for browser purchases.
  • PostHog for usage metrics and approximate location; Sentry for technical error and performance reports.
  • Authorities, if required by law.

11. Retention

  • Audio: not retained.
  • Local scores: until you clear site or app data.
  • Account and sessions: the authentication record and active sessions are removed from the service when the account is deleted.
  • Credits and surveys: balances, credit events, drafts, and answers stay linked to the account until deletion and are removed from the active database at that time.
  • Telemetry: our operational target is to resolve or escalate a case within 30 days; this is not a provider SLA or guarantee. We keep a PostHog request pending until there is verifiable evidence; request acceptance or a missing profile is not enough to mark deletion complete. Sentry always requires manual review. Unresolved cases are escalated on D30, with retries and review continuing through D90. We keep the technical identifiers encrypted for up to 90 days for retries and late-event audits, including after an initial confirmation. At D90, we delete those identifiers; if deletion is still unverified, only an operational record under a random reference with unresolved status remains.
  • Authentication database backups: we keep at most seven verified copies created within the last seven days. Before promoting a restored database, we reconcile deletion records created after its snapshot so deleted accounts are not reintroduced. Technical logs follow operational, security, and legal retention needs.
  • Deletion notices and Sign in with Apple: the email address used for notices is retained encrypted for up to 30 days. If a request is still pending, we may send a status notice about seven days before the target. A completion email is queued only after both providers have evidence of deletion and is not sent after D30. An Apple refresh token is retained encrypted only to attempt revocation and is removed when revocation finishes or within 30 days; if revocation cannot be completed, the app may ask you to revoke it manually.
  • Purchase and subscription data: under Apple, RevenueCat, and Stripe policies. Deleting the Musizz account does not cancel an App Store subscription. Browser subscriptions are canceled when RevenueCat processes deletion of the customer record.

12. Your rights

You may request confirmation of processing, access, correction, anonymisation, deletion, portability and information about sharing, and you may withdraw consents. Contact: [email protected].

  • Refuse the microphone in system settings.
  • Delete app or site data.
  • Manage or cancel an App Store subscription on iPhone or iPad in Settings > [your name] > Subscriptions.
  • Cancel a browser subscription at Account > Manage subscription in Musizz or through the link in RevenueCat Billing confirmation and renewal emails. Premium access continues until the end of the paid period.
  • Deleting your Musizz account does not cancel an App Store subscription. A browser subscription is canceled when RevenueCat processes deletion of the customer record.

Supervisory authority in Brazil: Autoridade Nacional de Proteção de Dados (ANPD).

13. Children

Musizz is intended for a general audience and was not designed specifically for children under 13. Check the age rating shown in the store for your country or region. Parents and guardians may contact the email provided in this policy with privacy questions or requests concerning a child’s or teenager’s data.

14. International transfers

Usage and diagnostic data sent to PostHog and Sentry are transferred to and processed in the United States. These transfers follow the providers’ applicable terms and safeguards. Other providers may also process data outside Brazil under their own configurations and policies.

15. Changes

We may update this policy. The date at the top will change. Material changes to data collection, use, sharing, or controls will be reflected here before or when the change takes effect, as required by applicable law.

16. Contact and documents

Terms of Use: https://musizz.app/terms. This policy: https://musizz.app/privacy.