Privacy Policy

1. Who we are

gugudan ("gugudan", the "app", "we", "us") is a voice-based multiplication-tables practice app for elementary-school children. The app is operated by Semolab (세모연구소), a business registered in the Republic of Korea [TBD — confirm with counsel: whether the business registration number / postal address must be published here]. You can reach us at hello@gugudan.app.

This policy explains what information the app handles, with a focus on children, and how parents and guardians can exercise their rights. It is written to follow the U.S. Children's Online Privacy Protection Act (COPPA).

2. Our approach to children's data

gugudan is designed for children, so we collect as little as possible:

• There is no sign-up and no account. We do not collect a child's name, age, birthday, email address, phone number, contacts, location, or photos.
• The app works fully in keyboard mode, in which nothing leaves the device.
• The only information that ever leaves the device is the child's spoken answer, and only when a parent has enabled the optional voice-grading feature (see Sections 4 and 5).

3. Information we handle

3.1 Stored only on the child's device

The following are stored only on the device and never sent to a company server. They contain no name, age, or other identifying details, and are removed when the app is uninstalled:

• Learning records (problems solved, correct/incorrect history)
• In-progress session state and per-table study statistics
• Language setting
• A consent record (the date/time of consent, the items consented to, and the disclosure version)

3.2 Handled only when voice grading is ON

• The child's spoken answer (audio). A short spoken answer to a multiplication question (for example, "twenty-one"). It is used only to convert speech to text so the app can grade the answer.
• A device-integrity token (Firebase App Check). A token used only to block automated abuse of our relay. It is not personally identifying and is generated only while voice grading is enabled.

We do not create a voiceprint, perform speaker identification or any biometric analysis, use the audio to identify the child, profile the child, or use the audio to train any model.

4. How the spoken answer is processed

When voice grading is on, the child's spoken answer is sent over an encrypted (TLS) connection to gugudan's own relay server (operated by Semolab on Google Cloud, in the United States) and then to Google Cloud Speech-to-Text (United States) for transcription only.

• The audio is processed ephemerally — held in memory only for as long as it takes to transcribe the answer in real time.
• It is deleted immediately after transcription. Our relay is stateless and stores no audio on disk, in logs, or in any database, and the transcription service is configured not to retain, log, or train on the audio.
• There is no behavioral advertising, profiling, or tracking at any point.

5. Verifiable Parental Consent (VPC)

Before the optional cloud voice-grading feature is enabled for a child under 13, a parent or guardian must complete identity verification — a Government-issued ID check plus a Selfie — hosted by a third-party identity-verification provider [TBD — confirm provider; verification flow pending build for the U.S. launch].

• The verification is performed by the third-party provider. gugudan does not store the government ID image or the selfie from this process; we keep only a minimal record that consent was given (see Section 3.1 and Section 6).
• Voice grading stays off until this consent is completed. The app remains fully usable in keyboard mode without it.
• A parent can withdraw consent at any time by turning voice grading off in the app's Settings, which stops any further transfer of the spoken answer immediately.

6. Retention and deletion

• Spoken answer (audio): deleted immediately after transcription. We retain none of it.
• On-device data (learning records, statistics, settings, consent record): stored only on the device and removed when the app is uninstalled. We do not store this on a server.
• Consent record: the device-local record is kept until the app is uninstalled. If a de-identified server-side receipt of consent is kept, it is retained for no more than one year and then deleted. Such a receipt contains only the date/time of consent, the items consented to and the disclosure version, and the fact that verification occurred — never a phone number, name, or government identifier.

We store no personal information about a child on a company server, so there is no server-side profile to retrieve or purge.

7. Parental rights

As a parent or guardian, you may:

• Review the information the app handles about your child (the categories are listed in Section 3);
• Refuse further collection by turning off voice grading in Settings, or by uninstalling the app;
• Delete on-device data by uninstalling the app. The spoken answer is never retained, so there is nothing to delete after transcription.

Because we keep no personal information about your child on a server, remote retrieval is limited by design. For any request or question, contact us at hello@gugudan.app and we will respond without undue delay.

8. Third parties and processors

We do not sell children's personal information and do not disclose it to third parties for their own purposes. The spoken answer is shared only with the service providers below, solely to provide the voice-grading feature:

9. Security

• Data in transit is encrypted with TLS.
• The relay is stateless and stores no audio.
• Learning records are stored on the device only.
• Device-integrity checks (App Check) help block abuse.
• We minimize what we collect — no account, no identifying details.

10. No tracking, ads, or analytics

The app uses no cookies, no advertising, and no analytics or crash-reporting tools. This website also uses no analytics or tracking. The only automatically generated value is the device-integrity token described above, and only while voice grading is on.

11. Changes to this policy

We may update this policy as the law, our service, or our legal review changes. When we do, we will post the updated policy here with a new effective date. For any change that materially affects how we handle children's information, we will obtain parental consent where the law requires it.

12. Contact

Semolab (세모연구소) · hello@gugudan.app