Privacy Policy

What data we collect, why, and what rights you have.

Last updated: July 20, 2026

1. Introduction

This Privacy Policy explains how CoreLink ("we", "us") collects, uses, and protects the personal data of users of the QuizMasters app (available on iOS and Android, "the App") and the website quizmasters.corelink.gr ("the Website"). By using the App or the Website, you accept the practices described here.

2. Data controller

The data controller for your personal data is CoreLink. For any question about your personal data, contact info@corelink.gr.

3. What data we collect

3.1 Account data

The App is fully playable without an account ("guest mode"). The following is only collected if you choose to register for online features:

  • Email address
  • Password (always stored hashed/encrypted — never in plain text)
  • Display name (a nickname you choose)
  • Country, and optionally region

3.2 Gameplay and social data

If you have an account, we store: per-round scores (category, game mode, points, correct answers, date), achievements, daily play streaks, live duel history (opponent, score, result), friends list/requests, and asynchronous challenge results.

3.3 Notification data

If you allow notifications, we store a device token (APNs for iOS or Firebase Cloud Messaging for Android) so we can send you challenge and duel alerts.

3.4 Data that never leaves your device

The profile photo (avatar) you choose is stored locally on your device only — it is never uploaded to our servers. The same applies to the local (guest) leaderboard, guest-mode category unlock progress, and appearance preferences (light/dark mode).

3.5 Advertising, analytics, and crash reporting

In some builds of the App (notably Android) we use:

  • Google AdMob — shows one ad after each finished round. AdMob may collect your device's advertising ID and ad-interaction data.
  • Google Firebase (Analytics, Crashlytics, Performance Monitoring, Cloud Messaging) — collects usage statistics, crash reports, and performance data, to help us improve the app.

These tools may identify your device via an advertising/device identifier, not by your name.

4. Why we process your data

  • To run your account, the online leaderboard, duels, and friends — legal basis: performance of a contract (GDPR Art. 6(1)(b)).
  • To send you challenge alerts — legal basis: your consent (you can withdraw it from your device's notification settings).
  • For advertising and usage statistics — legal basis: consent, where required by local law (e.g. EU/EEA), or legitimate interest for basic, non-personalized analytics.
  • For security and abuse prevention — legitimate interest.

5. Who we share data with

We never sell your data. We only share it with:

  • Our server hosting provider, where our database is hosted.
  • Apple Inc. and Google LLC — for purchase authentication, push notifications (APNs/FCM), and app distribution through their stores.
  • Google LLC (Firebase, AdMob) — for analytics, crash reporting, and advertising.

Each third-party provider processes data according to its own privacy policy.

6. International data transfers

Some of the providers above (e.g. Google, Apple) may process data on servers outside the European Economic Area. In these cases, we rely on the safeguards provided by that vendor (such as the EU Standard Contractual Clauses).

7. How long we keep your data

We keep your account data for as long as your account stays active. If you request deletion, we delete your data within 30 days, unless the law requires us to retain specific records for longer.

8. Security

We use encryption in transit (HTTPS), hashed password storage, and expiring session tokens to protect your data. No system is 100% secure, but we take reasonable technical and organizational precautions.

9. Your rights

Regardless of your location, we recognize your right to:

  • Request a copy of the data we hold about you (right of access)
  • Request correction of inaccurate data
  • Request deletion of your account and data ("right to be forgotten")
  • Request your data in a portable format (data portability)
  • Object to processing or withdraw consent at any time
  • Lodge a complaint with the Hellenic Data Protection Authority, or your local supervisory authority, if you believe your rights have been violated

10. How to exercise your rights / delete your account

Account deletion is currently handled on request: email info@corelink.gr from your account's email address with the subject "Account deletion". We will complete the deletion within 30 days.

An in-app account deletion option is planned for an upcoming release.

11. Children and age limit

Account creation is not directed at children under 16 (or the minimum digital-consent age in your country). If we learn we've collected a child's data without appropriate parental consent, we will delete it promptly.

12. Cookies and our website

The website quizmasters.corelink.gr does not use tracking or analytics cookies. It loads fonts from Google Fonts, which exposes your IP address to Google while the page loads — see Google's privacy policy for details.

13. Changes to this policy

We may update this policy from time to time. The date at the top of the page shows when it last changed. Material changes will be announced inside the App.

14. Contact

CoreLink — info@corelink.gr