Think Math Privacy Policy
Last updated: April 24, 2026
"Think Math" (the "App"; distributed in Korea as "생각수학"), provided by Hasegi Inc. (the "Company"), respects the privacy of its users and complies with applicable laws. This policy explains what information the App handles, how it is used, how it is retained or deleted, and your rights as a user.
Summary
This App does not operate any server and does not collect or transmit personally identifiable information. All learning data — including wrong-note entries, handwriting, attached images, study progress, and settings — is stored only on the user's device. The Company has no access to any of it. Uninstalling the App permanently removes all such data.
1. Information Handled
(1) Information you create (stored on your device only)
- Wrong-note entries (problems, solutions, memos)
- Handwriting / signature drawings
- Photos taken with the camera or selected from your album for wrong notes
- Study progress, bookmarks, and recently viewed concepts
- In-app settings (notification time, etc.)
All of the above is stored only inside your device's local storage (SharedPreferences and the app's sandboxed file directory). It is never transmitted to the Company's servers or to any third party, and is removed when you uninstall the App.
(2) Information accessed via permissions
- Camera (optional): used only when you take a photo to attach to a wrong note. Photos are saved to the App's local storage and are not transmitted.
- Photo library (optional): used only when you pick an existing image to attach to a wrong note.
- Notifications (optional): used to schedule local study reminders on your device. No data is sent externally.
(3) Advertising-related information
The App uses Google AdMob to display ads. Under Google's privacy policy, AdMob may collect the following information:
- Advertising identifiers (Android Advertising ID / iOS IDFA)
- IP address, device model / OS version, app version, language and country settings
- Ad impression and click event information
iOS users: IDFA is used for personalized ads only if you allow tracking via Apple's App Tracking Transparency (ATT) prompt. If you decline, only non-personalized ads are shown and all App features remain available.
International transfer: The advertising-related information above may be transmitted to and processed on servers operated by Google LLC (including in the United States) for ad delivery. Details are described in Google's privacy policy (policies.google.com/privacy).
2. Purposes
- Providing math concept exploration and learning content
- Storing user-created wrong notes and study progress on-device
- Delivering local study-reminder notifications
- Supporting the App through advertising
3. Third-Party Services
The App uses the following third-party services, which are governed by their own privacy policies.
4. Retention and Deletion
- User-created data (wrong notes, handwriting, attached images, study progress, settings) is stored only on your device. It remains until you delete it from the App or uninstall the App.
- Because the App does not store user data on any server, no separate deletion request is necessary.
- Uninstalling the App permanently removes all locally stored data. Recovery is not possible.
5. Your Rights
- You may delete individual wrong notes, study records, and attached images at any time from within the App.
- Camera, photo library, notification, and ATT permissions can be changed at any time in your device settings.
- You may reset your advertising identifier or opt out of personalized ads in your device's ad settings.
- Uninstalling the App removes all data stored on your device.
6. Children's Privacy
Think Math is an educational app suitable for users of all ages, including children under the age of 14. The App does not require account registration and does not knowingly collect personally identifiable information from children. We encourage parents and guardians to supervise their children's use of the App. For inquiries regarding deletion of locally stored data or App management, please contact us using the information below.
7. Data Security
- Technical measures: Learning data is stored only inside the App's sandboxed local storage, which is isolated from external access by the operating system.
- Data minimization: We only handle the minimum information necessary to provide the service.
- Third-party SDKs: We use only well-established SDKs (e.g., Google AdMob) and rely on their providers' privacy practices.
8. Changes to this Policy
This policy may be updated to reflect legal or service changes. Updates will be announced through the App or this page.
9. Contact