Mathstack — Privacy Policy

Last updated: February 22, 2026

Hazerim Interactive Entertainment, UAB ("we", "us", or "our") develops and publishes Mathstack, a strategic number puzzle game. This Privacy Policy explains what data we collect, how we use it, and your rights regarding that data.

This policy applies to the Mathstack app (bundle ID: com.hazerim.mathstack) available on the Apple App Store.

1. Data We Collect

1.1 Gameplay Data (Collected Automatically)

When you play Mathstack, we collect the following gameplay metrics to improve the game experience:

Difficulty level selected (Easy, Medium, Hard)
Game session identifiers (random seed IDs, not linked to your identity)
Game performance: score, number of moves, time taken
Game outcome: completed, abandoned, or restarted
Screen views within the app (e.g., Home, Leaderboard, Profile)

1.2 Game Center Data (Optional)

If you choose to sign in with Apple Game Center, the following data is accessed:

Your Game Center display name and profile photo
Leaderboard scores and rankings
Achievement progress

Game Center authentication is entirely optional. You can play the full game without signing in.

1.3 Advertising Data (Google AdMob)

Mathstack displays ads through Google AdMob. When ads are shown, Google may collect:

Device advertising identifier (IDFA, subject to your App Tracking Transparency choice)
IP address (used for approximate location to serve region-appropriate ads)
Device information (model, OS version, screen size)
Ad interaction data (impressions, taps)

You can opt out of personalized ads through your device settings. If you decline the App Tracking Transparency prompt, only contextual (non-personalized) ads will be shown.

1.4 Data We Do NOT Collect

Name, email, phone number, or other contact information
Precise location data
Photos, contacts, or files from your device
Health, fitness, or biometric data
Financial or payment data (the app has no in-app purchases)
Browsing history or data from other apps

2. Third-Party Services

Mathstack integrates the following third-party services:

Service	Purpose	Data Processed	Data Location
PostHog	Analytics	Gameplay events, screen views (pseudonymized)	European Union
Google AdMob	Advertising	Device identifiers, ad interactions, IP address	United States
Apple Game Center	Leaderboards & achievements	Player profile, scores, achievement progress	Managed by Apple

We do not sell, rent, or lease your personal data to any third party.

Links to third-party privacy policies:

3. How We Use Your Data

Improve game balance and difficulty by analyzing gameplay patterns
Identify and fix bugs or crashes
Display advertisements to support the free version of the app
Power leaderboards and achievements through Apple Game Center

4. Data Storage and Retention

Game progress, statistics, and player profile data are stored locally on your device only. This data is never transmitted to our servers.

Analytics data sent to PostHog is retained for 12 months, after which it is automatically deleted.

Advertising data is managed by Google according to their data retention policies.

Game Center data is managed by Apple and retained according to Apple's policies.

5. Cookies and Tracking Technologies

Mathstack is a native mobile app and does not use browser cookies. However, our third-party partners may use the following technologies:

PostHog: Anonymous session identifiers to group events from the same play session
Google AdMob: Device advertising identifier (IDFA) for ad personalization, subject to your consent via the App Tracking Transparency prompt

6. Consent and Your Choices

Mathstack respects your privacy choices:

App Tracking Transparency: On first launch, iOS will ask whether you allow tracking. If you decline, Google AdMob will only serve non-personalized, contextual ads
Game Center: You can choose not to sign in. The game is fully playable without Game Center
Ad personalization: You can change ad preferences in your device Settings > Privacy & Security > Apple Advertising

7. International Data Transfers

Analytics data is processed by PostHog within the European Union. Advertising data processed by Google AdMob may be transferred to the United States. For such transfers, we rely on Standard Contractual Clauses approved by the European Commission and Google's compliance with applicable data protection frameworks.

8. Children's Privacy

Mathstack is rated 4+ on the App Store and is suitable for all ages. We do not knowingly collect personal data from children under 16. The app does not require account creation or personal information to play.

When ads are shown to users identified as children (based on age or parental settings), Google AdMob serves only limited, age-appropriate ads in compliance with COPPA and other applicable regulations.

9. Your Rights (GDPR / EEA Users)

If you are located in the European Economic Area, you have the right to:

Request access to the data we hold about you
Request correction or deletion of your data
Object to or restrict data processing
Request data portability
Withdraw consent at any time (without affecting prior processing)

Since we do not collect personally identifiable information directly, most data we process cannot be linked back to you. If you need to exercise any rights, contact us at contact@hazerim.com.

10. California Residents (CCPA)

If you are a California resident, you have additional rights under the California Consumer Privacy Act. We do not sell personal information. You may request disclosure of the categories of data collected or request deletion by contacting us.

11. Changes to This Policy

We may update this Privacy Policy when we add new features or integrations. Changes will be posted on this page with an updated revision date. Continued use of the app after changes constitutes acceptance of the updated policy.

12. Contact Us

If you have questions about this Privacy Policy or want to exercise your data rights:

Hazerim Interactive Entertainment, UAB
Ukmerges g. 228a-8, 07161 Vilnius, Lithuania
contact@hazerim.com