Cube Brain Trainer Privacy Policy

Effective: August 26, 2026 (first published July 6, 2026)

Cube Brain Trainer (the "app") values your privacy and processes only the minimum information necessary. This policy explains what information the app processes, why it is processed, and what choices you have.

1. Information we do not collect

The app does not require sign-up or login, and it does not collect information that directly identifies you, such as your name, email address, or phone number. Your learning progress, practice records, and app settings are stored only on your device and are never sent to our servers.

2. Information processed through usage analytics

In the app, we use Google Firebase Analytics to improve it. The following is processed in anonymous form:

An app instance identifier (a random value generated per installation — never linked to your name or email)
Usage events such as screen views, lesson starts, completions and drop-offs, and time-attack starts and finishes
Minimal values attached to those events (learning deck and case identifier, the step number at drop-off, and time-attack duration)
Device model and OS information, and an approximate location inferred from IP address (country/region level)

We do not collect advertising identifiers (Apple's IDFA).

This information is used only to understand where learners get stuck so we can improve the learning flow. We do not use it to identify you, and we never sell it to third parties. Your accumulated progress and individual practice records are stored only on your device and are not transmitted. For details on Google's data handling, see the Google Privacy Policy (https://policies.google.com/privacy).

2-1. Information processed on this website

This website (cube-brain-trainer.expo.app) uses Google Analytics, together with cookies and similar technologies, to understand how visitors arrive here. The following is processed in anonymous form:

A random per-browser identifier stored in a cookie (never linked to your name or email)
The pages you visit and how long you stay
How you arrived (the referring website address and any campaign tags in the link)
In-page actions such as clicking an app store button
Browser and device type, and an approximate location inferred from IP address (country/region level)

This is used only to understand how people find us so we can improve what we explain here. We do not use it to identify you, and we never sell it to third parties. Website analytics are not linked to your in-app activity — they are entirely separate.

If you are visiting from Europe, analytics cookies are set only after you accept. You can decline in the notice shown at the bottom of the page; declining does not restrict your use of this site in any way.

3. Advertising (not shown in the current version)

The current version of the app does not display ads, and therefore no information is processed for advertising purposes.

If we introduce ads in the future, we will update this policy in advance before doing so. At that point the following may be processed:

Advertising identifiers (Apple's IDFA on iOS, the Android Advertising ID)
Device information and approximate location (country/region level)
Ad interaction data, such as impressions and clicks

We would then show the App Tracking Transparency (ATT) prompt on iOS and a consent message (Google UMP) in the EEA/UK and other applicable regions. For details on Google's data handling, see the Google Privacy Policy (https://policies.google.com/privacy).

4. Your choices and consent

You can reset your advertising identifier or opt out of personalized ads at any time in your device settings (iOS: Settings > Privacy & Security > Tracking / Android: Settings > Google > Ads).
App Tracking Transparency (ATT) and the Google UMP consent message apply from the point ads are introduced per section 3 above; they are not shown in the current version.
You can opt out of this website's analytics by blocking cookies in your browser or by installing Google's opt-out add-on (https://tools.google.com/dlpage/gaoptout).

5. Children's privacy

The app is not primarily directed at children, and we do not knowingly collect personal information from children under 13 — or under a higher minimum age where local law requires one (for example, 14 in the Republic of Korea).

6. Data retention and deletion

Records stored on your device are removed when you delete the app. Retention and deletion of usage-analytics information are governed by the Google policy above.

7. Changes to this policy

This policy may be updated to reflect changes in applicable laws or in the service. Updates will be posted on this page together with a new effective date.

8. Contact

Privacy inquiries: lastchoice86@naver.com