SleepLoopSleepLoop Privacy Policy
Effective date: November 5, 2026. The Korean version is the official text; this is a translation.
Juho Choi ("the operator") operates SleepLoop, a sleep wellness research app for Android phones and Wear OS watches ("the app"), and protects users' personal information under the Personal Information Protection Act of Korea. The app is not a medical device and does not diagnose or treat any condition.
1. Purpose
- Estimating the sleep state from signals measured during sleep and adjusting ambient sound accordingly
- Checking and improving how the app works, and research analysis (statistics are used only in a form that cannot identify individuals)
- Handling users' deletion requests
2. Information processed
We do not collect names, phone numbers or email addresses. Each user is identified only by a random research ID created by the app.
| Category | Items | Consent |
|---|---|---|
| Biosignals | Heart rate, inter-beat intervals, acceleration (movement), skin temperature, on-body status, raw PPG (supported devices only) | Required |
| Data sent to the server | 30-second summaries (sleep state, sound control log), session information (device model, app version), basic body information (birth year, sex, height, weight) | Required |
| Raw data | Raw signals at 1-second resolution, ambient noise level per second | Optional |
| Ambient noise level | A number (dB per second) computed from the phone microphone. Audio is never recorded or stored | Optional |
| Health app records | Sleep sessions and stages, blood oxygen, heart rate (session period only) and the Samsung Health sleep score, read from Health Connect and Samsung Health | Optional |
| Morning survey | Sleep quality, time to fall asleep, awakenings, sound comfort, discomfort | Optional |
Sleep and heart information is health information (sensitive information) under Korean law, so consent is requested separately for each item. The app can be used without optional items.
3. How it is collected
Consent is requested item by item when the app is first opened. Data is collected only during sleep sessions started by the user. Health Connect and Samsung Health records are read only with consent and permission; the app writes nothing to them.
4. Retention and deletion
- Retention: until the research ends, up to 3 years, or until the user deletes the data.
- "Delete my data" in the app immediately deletes all server records of that research ID. Server backups are kept for 14 days, so deleted data disappears from past backups within 14 days.
- At the end of the retention period, data is deleted so that it cannot be recovered.
5. Sharing with third parties
We do not share personal information with third parties. Research results are published only as statistics that cannot identify individuals.
6. Service providers and overseas transfer
Cloudflare, Inc. (USA) relays the encrypted connection between the app and the research server; it does not store this data. The research server is a computer in Korea managed by the operator.
7. Your rights
- Withdraw optional consents at any time (app settings)
- Delete all of your data (app settings → Delete my data)
- Request access, correction or suspension of processing (contact below)
8. Security measures
- Encrypted connection (TLS) between the app and the server
- No identifying information other than the research ID; access limited by device tokens
- Restricted admin access, server access logs, daily backups
- Ambient noise is reduced to a number and the audio is discarded immediately
9. Privacy officer
Juho Choi · privacy@flio.co.kr
10. Changes
Changes to this policy are announced on this page and in the app at least 7 days before they take effect.