Privacy Policy
Update notice (posted October 27–28, 2026) We added how Sai occasionally shows Google AdMob full-screen ads during free use, and the purchase information used for the ad-free paid subscription (Sai Plus) (sections 1, 3, 4 and 8). The updated policy applies from November 4, 2026, and no ads are shown before then. The paid subscription items apply from the time you buy a subscription.
Neural Lab (“we”, “us”) operates Sai, a couple app for sharing photos, plans, diaries, chats and location with one partner on iPhone and Android (the “Service”). This policy explains what information the Service processes, why, where it goes, and when it is deleted. Neural Lab is the controller of your personal information.
1. Information we process and why
| Category | Items | Purpose |
|---|---|---|
| Account and sign-in (required) | Name; email and password hash (email sign-up); Apple or Kakao account identifier and encrypted sign-in tokens; sign-in sessions | Identifying you, keeping you signed in, account recovery, preventing abuse |
| Couple space (required) | Connection with your partner, the date you started dating, plans and anniversaries (including repeat, duration and reminder settings), photos, diaries, comments, messages, timestamps | Providing the shared calendar, journal and chat for the two of you |
| Profile (optional) | Gender, onboarding progress | Tailoring features and settings |
| Period records (optional, health data) | Start and end dates, notes, sharing settings | Keeping your own cycle log and predicting upcoming dates. Processed only if you turn it on; private by default. Predictions are calculated on your device and never sent to your partner. |
| Location (optional) | Latest location (latitude, longitude, accuracy, time), places you stayed together and footprints, location-sharing records (recipient and time) | Sharing your location with your connected partner and recording the paths you walked together |
| Photo library (optional, iPhone) | Time and location of photos you allow | Making postcards from photos that match places you stayed together. Matching happens on your device; only photos turned into postcards are uploaded. |
| Notifications (optional) | Device push token (Apple APNs, Google FCM), notification settings | Sending message and comment alerts. Notifications never contain message text. |
| Support | Email address, your message | Answering you, verifying your account, handling deletion requests |
| Generated automatically | Access logs, error logs, IP address (server logs for security) | Keeping the Service stable and secure |
| Paid subscription (optional) | Store (App Store or Google Play), product, transaction identifiers, subscription status and expiry, auto-renew status, Google purchase token, an identifier that links the purchase to your account | Verifying purchases, giving both of you ad-free use, applying renewals and refunds, preventing abuse. We never receive card numbers or other payment details. |
| Ads (free use) | Collected by the Google Mobile Ads SDK when an ad is requested: IP address, device and OS information, app instance identifiers (not the advertising ID), ad impressions and clicks, diagnostics | Serving full-screen ads, frequency capping, measurement and click-fraud prevention. We request non-personalized ads only and never use app content such as entries, photos, location or period records for ads. |
During free use, Sai may occasionally show a Google AdMob full-screen ad at a natural break, such as after you save an entry or close one. Ads are never shown on the day you install the app, and at most once an hour and three times a day. We request non-personalized ads only, do not use the advertising ID, and do not use separate analytics tools. Couples on the paid subscription (Sai Plus) see no ads.
Legal bases (EEA, UK and similar laws)
We process account and couple-space information to perform our contract with you; location, period records and photo matching on the basis of your consent, which you can withdraw in the app at any time; and security logs on the basis of our legitimate interest in protecting the Service.
2. How long we keep information
- Your account and records are kept until you delete your account. When you delete it, we immediately delete your account, sessions, the records, photos, comments, messages and period records you created, and the locations and footprints of your current space.
- When you disconnect from your partner, location and period sharing stop, and your own records stay in “My earlier entries”, visible only to you.
- Your latest location is deleted when you stop sharing or your chosen sharing time ends. Location samples used to calculate footprints are deleted after 24 hours.
- Operational backups exist for disaster recovery and are deleted automatically 7 days after creation. If we ever restore from a backup, we delete data of deleted accounts again before resuming service.
- Encrypted Apple and Kakao tokens are kept for up to 30 days after account deletion so we can revoke the sign-in connection, and are deleted as soon as revocation finishes.
- As required by Korea’s Act on the Protection and Use of Location Information, we keep records of location provision (who received a location and when, without coordinates) for 6 months.
- Support emails are deleted 1 year after the request is resolved.
3. Sharing with third parties
We do not sell or share your personal information with third parties, and we do not share it for cross-context behavioral advertising. Showing your records and location to the partner you connected with is the core function of the Service, and you control what is shared. We disclose information only when required by law. When ads are shown during free use, Google LLC receives the “Ads” items in section 1 directly through the Google Mobile Ads SDK and uses them to serve and measure ads and prevent fraud, retaining them under Google’s policies.
4. Service providers and international transfers
Neural Lab is based in the Republic of Korea. To run the Service, we use the providers below, and your information may be transferred to and processed in the countries listed.
| Recipient | Task | Country and method | Items | Retention |
|---|---|---|---|---|
| Railway Corporation | Server hosting and data storage | Netherlands (Amsterdam); sent over the network while you use the Service | All Service information in section 1 | Until the contract ends or the periods in section 2 |
| Google LLC (Firebase Cloud Messaging) | Android notifications | United States and others; sent when a notification is triggered | Push token, notification type and target identifier | Per Google’s policy after delivery |
| Apple Inc. (APNs, Sign in with Apple, Apple Maps) | iPhone notifications, Apple sign-in, maps outside Korea on iPhone | United States and others; sent when notifying, signing in or viewing the map | Push token, Apple sign-in token, map area and positions being displayed | Per Apple’s policy |
| Apple Inc., Google LLC (App Store and Google Play billing) | Subscription payments and purchase status checks | United States and others; sent when buying or checking status | The “Paid subscription” items in section 1 | Per each company’s policies |
| Google LLC (AdMob) | Serving and measuring full-screen ads during free use | United States and others; sent when an ad is requested | The “Ads” items in section 1 | Per Google’s policies |
| OpenFreeMap (map tiles based on OpenStreetMap) | Maps outside Korea on Android | European Union; sent when viewing the map | IP address and the map area being requested | Per the provider’s policy |
| Resend, Inc. | Verification code emails | Japan (Tokyo) sending servers; sent when an email is sent | Email address, verification code | Per Resend’s policy after sending |
| Kakao Corp. | Kakao sign-in, maps in Korea | Republic of Korea | Kakao account identifier, map requests | Per Kakao’s policy |
Where required, we rely on appropriate safeguards for these transfers. If you do not want your information transferred abroad, you can choose not to sign up or delete your account, although you will then be unable to use the Service. You can turn off notifications in your device settings.
5. Children
Sai is for people aged 14 or older, or the minimum age required in your country if it is higher (for example, 16 in some EEA countries). If we learn that we hold information about a child below that age, we delete it promptly.
6. Your rights
You can access, correct, export or delete your information, and ask us to restrict or stop processing it. In the app, go to Us → Settings to edit your information, export your data, stop sharing or delete your account. You can also email contact@neuralab.kr; we respond within 10 days (and always within the period required by your local law).
- EEA and UK: you also have the right to data portability, to object to processing based on legitimate interests, to withdraw consent at any time, and to lodge a complaint with your local data protection authority.
- California: you have the right to know, delete and correct personal information, and to not be discriminated against for exercising these rights. We do not sell or share personal information, and we do not use sensitive personal information for purposes other than providing the Service.
- Japan: you may request disclosure, correction, suspension of use, or deletion of retained personal data, and information about the providers and transfers above, under the Act on the Protection of Personal Information.
You can withdraw consent to location sharing and period sharing directly in the app.
7. Security
- All communication is encrypted with HTTPS. Passwords are stored as one-way hashes, and external sign-in tokens are encrypted.
- The server checks permissions so that records and photos are visible only to the two people in the same space.
- Records waiting to be sent are encrypted on your device, and sign-in information is stored in the iPhone Keychain or Android Keystore.
- Operational access is limited to our representative.
8. Cookies and identifiers
The app does not use cookies. When showing ads during free use, the Google Mobile Ads SDK may use device information such as app instance identifiers. We do not use the advertising ID (IDFA on iPhone, Android advertising ID) and do not request personalized ads. In the UK, the EEA and Switzerland, Google’s consent screen asks for your choice, and you can change it any time in Us → Settings → Ad privacy settings. See how Google uses information.
9. Contact
Privacy officer: Minseo Lee (Representative) · contact@neuralab.kr
10. Changes
We will announce changes in the app and on this page 7 days before they take effect, or 30 days before for changes that affect you adversely.