Mental Math Drills: Rank Test (iOS app) Privacy Policy

Last updated: November 3, 2026

This page is an English translation of the Japanese privacy policy.

1. Operator

This policy describes how information is handled in the iOS app “Mental Math Drills: Rank Test” (Japanese name: 暗算ドリル - 計算力ランク判定; the “App”).

Operator: D-HUB+
Contact: info@dhub-plus.com

2. Information collected

The App and the third-party services built into it (the advertising, analytics and purchase SDKs listed in section 4) may collect the information below. This information may be linked to you (your device) through device or app identifiers. Your name, email address and similar details are not collected. Information that may be used to track you across other companies’ apps and websites (“tracking”; marked “may be used for tracking” below) is used for tracking only if you allow it in your device’s App Tracking Transparency (ATT) permission prompt (see section 7).

  • Device ID (identifiers assigned by the advertising and analytics SDKs, and, if you allow it through ATT, Apple’s advertising identifier (IDFA)) — used for advertising and analytics. May be used for tracking.
  • Product interaction usage data (how you use the App, such as scores, correct-answer streaks and progress, and your interactions with ads) — used for analytics and advertising. May be used for tracking.
  • Purchase history (purchase and restore status of in-app purchases, and product IDs) — used to provide App features and for analytics.
  • Advertising data (ad impression and viewing events, information about ad requests, etc.) — used for advertising. May be used for tracking.
  • Crash data (information about abnormal terminations) — used for analytics.
  • Performance data (launch time, ad loading time, etc.) — used for analytics and advertising. May be used for tracking.
  • Other diagnostic data (operational status data, etc.) — used for analytics and advertising. May be used for tracking.
  • Coarse location (country or region estimated from your IP address, etc.; the device’s location services are not used) — used for advertising and analytics. May be used for tracking.

Play data (detailed records such as scores, correct-answer streaks, progress, coins and items) is stored only on your device (UserDefaults). I do not operate any server, so these detailed records themselves are never sent off the device. Deleting the App also deletes this data stored on the device. However, as the “product interaction usage data” above, part of these records, such as in-play scores and correct-answer streaks, is sent to Google Firebase Analytics as described in sections 4 and 5. The App has no account registration or sign-in, and does not collect contact information such as email addresses.

Sending analytics data through Firebase Analytics follows the result of the ad consent check (UMP) (version 1.0.2 and later). In regions where no consent dialog is required, such as Japan, it is sent from the first launch of the App (it is not sent on a launch where the consent-check request fails). In these regions, the App has no setting to stop analytics. In regions where a consent dialog is required, it is not sent before you give consent or after you withdraw consent.

3. Purposes of use

  • Providing and operating the App
  • Improving features and quality
  • Serving ads and measuring ad performance (including serving ads tailored to you, if you allow it through ATT)
  • Processing purchases and restoring purchases

4. Third-party services used

The App may use the following third-party services.

  • Google AdMob (advertising)
  • Google Firebase Analytics (usage analytics; from version 1.0.2, follows the result of the ad consent check)
  • Apple StoreKit (in-app purchases)

Each service handles data in accordance with its provider’s privacy policy.

5. Sharing with third parties

The App provides the data described in section 2 to the providers of the services listed in section 4, for the roles below.

  • Google AdMob (serving ads and measuring ad performance) — device ID, product interaction usage data, advertising data, performance data, other diagnostic data, coarse location, crash data
  • Google Firebase Analytics (usage analytics) — device ID, product interaction usage data, purchase history (product IDs), performance data, other diagnostic data, coarse location
  • Apple StoreKit (purchase processing) — purchase history

This data sharing is limited to what is needed to provide the App’s features. I do not sell or provide your data to unrelated third parties of my own choosing. Each company handles data in accordance with its own privacy policy.

6. Data retention

Play data is stored only on your device (UserDefaults), and deleting the App also deletes the data on the device. Information collected by third-party services such as Google AdMob and Google Firebase Analytics is retained according to each company’s terms. I do not set my own retention periods for data collected by third-party services, and I do not provide a means by which I directly delete data stored in these services.

7. Tracking and your choices about ads

The App uses Google AdMob to show rewarded video ads that you choose to watch, and AdMob may use the data described in section 2 to track you across other companies’ apps and websites (“tracking”). For this reason, the App asks for your permission to track through App Tracking Transparency (ATT).

  • The permission prompt is shown when you launch the free version, after the ad consent check (below) has finished and allowed ads. This is normally the first launch, but if the consent check request fails on that launch or ads are not allowed, the prompt is not shown then and is shown on a later launch instead. Once you make a choice, it is not shown again. It is not shown to users who have purchased “Remove Ads”.
  • If you allow it: ads tailored to you (personalized ads) may be served using identifiers including the IDFA.
  • If you do not allow it: the IDFA is not included in ad requests, and non-personalized ads are shown. The App’s features are the same as when you allow it.
  • You can change your choice at any time in your device’s Settings > Privacy & Security > Tracking.
  • In some regions, an ad consent check by Google’s User Messaging Platform (UMP) is shown at launch or from the ad consent item on the App’s Settings screen. In the EEA, the UK and Switzerland it may be shown at launch, and users in areas covered by US state laws may see a message about US state laws from the item on the Settings screen. In regions where a consent dialog is required, if consent is not given (or is withdrawn), only limited, non-personalized ads are served, and no analytics data is sent through Firebase Analytics (version 1.0.2 and later). In regions where no consent dialog is shown, such as Japan, the ad consent check permits the use of ads, so Firebase Analytics is enabled from the first launch. In these regions, the App has no setting to stop analytics.
  • If you purchase “Remove Ads”, ads are no longer shown, but analytics still follows the result of the ad consent check (version 1.0.2 and later). In regions where no consent dialog is required, such as Japan, analytics data is sent. In regions where a consent dialog is required, analytics data is not sent unless you had given consent before the purchase. After the purchase the consent screen is no longer shown, so the App has no setting to withdraw consent.
  • The App’s features (other than ads) do not change based on your ATT and UMP choices.

8. Children’s privacy

The App complies with applicable laws and is mindful of protecting minors’ information.

9. Changes

This policy is updated as needed. Material changes will be announced in the App or on this page.