Privacy Policy

Data Controller

SD Group
helos@sd-group.gr
Greece

HELOS (“the App”) is operated by SD Group, based in Greece. This Privacy Policy explains how we collect, use, and protect your information when you use our mobile application.

1. Information We Collect and Legal Basis

1.1 Data Stored Locally on Your Device

The App stores all game data locally on your device, including:

• Game progress and statistics
• Vocabulary lists and quiz results
• User preferences (language, theme, sound settings)
• Streak and achievement data

Legal basis: This processing is necessary for the performance of the service you requested (Art. 6(1)(b) GDPR). This data is never transmitted to our servers or any third party. We do not have access to this data. If you uninstall the App, this data is permanently deleted.

1.2 Advertising Data (Google AdMob)

The free version of the App displays advertisements provided by Google AdMob. When you consent to advertising, Google may collect:

• Device identifiers (Advertising ID)
• IP address
• General location (country/region level)
• App usage data related to ad interactions

Legal basis:Your consent (Art. 6(1)(a) GDPR). Before any advertising data is collected, we request your explicit consent through a Consent Management Platform compliant with the IAB Transparency & Consent Framework (TCF 2.2). You may:

• Accept personalized advertising
• Accept non-personalized advertising only
• Reject all advertising data processing

You can change your consent at any time via Settings > Manage Ad Preferences. If you reject all advertising data processing, you will still see contextual ads that do not track you.

If you purchase the ad-free upgrade, no advertising SDK is initialized and no advertising data is collected.

This data is collected and processed by Google in accordance with Google's Privacy Policy.

1.3 Purchase Data (RevenueCat)

If you make a purchase (e.g., removing ads), the transaction is processed through the Google Play Store or Apple App Store. RevenueCat, our purchase management provider, may process:

• Transaction receipts
• Purchase status
• Anonymous user identifiers

Legal basis: This processing is necessary for the performance of a contract — specifically, to verify your purchase and provide the ad-free experience you paid for (Art. 6(1)(b) GDPR).

RevenueCat does not have access to your payment details. See RevenueCat's Privacy Policy.

2. International Data Transfers

Google AdMob may transfer data to servers located in the United States and other countries outside the European Economic Area (EEA). These transfers are protected by:

• The EU-US Data Privacy Framework (for US transfers)
• Standard Contractual Clauses (for other international transfers)

as described in Google's data transfer framework.

RevenueCat processes data in the United States under the EU-US Data Privacy Framework.

Local game data never leaves your device and is not subject to international transfers.

3. Data Retention

4. Data Sharing

We do not sell, rent, or share your personal information. The only third parties that receive data are:

• Google AdMob — advertising data (only with your consent)
• RevenueCat — purchase verification data (only if you make a purchase)

5. Children's Privacy

The App is not directed at children under the age of 16. We do not knowingly collect personal information from children. If you are a parent or guardian and believe your child has provided information through the App's third-party services, please contact us and we will take steps to delete such information.

6. Your Rights (EEA / GDPR)

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

• Access the personal data held about you (Art. 15)
• Rectify inaccurate data (Art. 16)
• Eraseyour data — “right to be forgotten” (Art. 17)
• Restrict processing of your data (Art. 18)
• Object to processing (Art. 21)
• Data portability — receive your data in a portable format (Art. 20)
• Withdraw consent at any time without affecting the lawfulness of processing based on consent before its withdrawal (Art. 7(3))

How to exercise your rights:

• Local data: Uninstall the App or clear its data in your device settings.
• Advertising consent:Go to Settings > Manage Ad Preferences to withdraw consent.
• Advertising identifier:Reset your Advertising ID in your device's privacy settings.
• Purchase data: Contact RevenueCat directly or email us.
• Other requests: Email us at helos@sd-group.gr. We will respond within 30 days.

7. Data Security

Local data is stored in your device's secure application sandbox. We do not transmit or store your game data on external servers. Third-party services (Google, RevenueCat) use industry-standard encryption and security measures.

8. Changes to This Policy

We may update this Privacy Policy from time to time. Changes will be reflected in the “Last Updated” date above. For material changes, we will notify you through the App. Continued use of the App after changes constitutes acceptance.

9. Contact Us and Supervisory Authority

If you have questions about this Privacy Policy or wish to exercise your rights, please contact us:

SD Group
Email: helos@sd-group.gr
Location: Greece

If you believe your data protection rights have been violated, you have the right to lodge a complaint with the Hellenic Data Protection Authority (HDPA):

Hellenic Data Protection Authority
Website: www.dpa.gr