Nonogram Duel
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Privacy Policy

Last updated: 2026-10-22 — version 1.0

This privacy policy explains how personal data is processed in the mobile app Nonogram Duel (the "app") and on this website.

1. Controller

Instant Media by Röllin
Holzhäusernstrasse 15
6313 Menzingen, Switzerland
Email: [contact@nonogram-duel.com — please set up this mailbox]

2. Data processing in the app

2.1 Local storage on your device (no transmission)

The app stores the following data exclusively on your device. It never leaves your device and is deleted automatically when you uninstall the app:

2.2 Google Firebase Analytics (usage analysis)

The app uses Google Firebase Analytics (Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland) to understand how the app is used. Processed data includes:

Purpose: improving the app, error analysis and usage statistics. The legal basis is our legitimate interest in improving our app (Art. 6 (1)(f) GDPR). Google transfers data to the USA among others, based on the EU Standard Contractual Clauses and the terms of Google Firebase and the Google Privacy Policy. Firebase Analytics data is stored for 14 months by default. You can prevent this analysis by uninstalling the app; transmission of advertising identifiers can be restricted in your device settings.

2.3 Online duels (Firebase Realtime Database)

During an online duel the following data is transmitted via Google Firebase servers and stored temporarily:

This data is visible to your opponent during the duel and is deleted immediately after the duel ends. No attribution to your identity is possible. No accounts are created and no email addresses or phone numbers are requested. Processing serves to run the game you requested (Art. 6 (1)(b) or (f) GDPR).

2.4 Friend challenge codes

After winning a puzzle you can create a "duel code" and share it yourself via a messenger of your choice (e.g. WhatsApp). The code contains the puzzle identifier, your time, your number of hints used and your display name. This transmission runs through the respective messenger provider, not through our systems; we have no insight. The recipient decodes the code exclusively locally in their app.

2.5 Anonymous gameplay statistics (telemetry)

To calibrate difficulty and the speed of computer opponents realistically, we store anonymous gameplay traces in our Firebase Realtime Database after completed puzzles: the sequence of your moves (blocks placed/removed and markings with timestamps), round duration, tier and mode — linked exclusively to your random installation identifier. Only in-puzzle moves are recorded; no conclusions about your identity are possible. The data is used for statistical analysis and deleted regularly. Legal basis: Art. 6 (1)(f) GDPR (legitimate interest in fair game balance).

2.6 Cloud sync (optional)

On request, the app stores your progress and settings under a random 8-character sync code in our Firebase Realtime Database. Entering the code on another device restores your progress there. Stored data: progress, settings and your display name — no email, no password, no contact details. Anyone who knows the code can see the progress; treat it like a password. You can stop the sync at any time by uninstalling the app; old cloud entries are deleted regularly. Legal basis: Art. 6 (1)(b) or (f) GDPR.

3. Website

When you visit this website, the hosting provider automatically processes technical access data (truncated IP address, date/time, requested page, browser type). This is technically required and deleted after a short period. Legal basis: Art. 6 (1)(f) GDPR (legitimate interest in a secure, stable operation). Hosting: Google Firebase Hosting, Google Ireland Limited. No tracking, no marketing cookies.

4. Advertising (preview)

The app is currently ad-free. We intend to include advertising via Google AdMob (Google Ireland Limited / Google LLC, 1600 Amphitheatre Parkway, Mountain View, CA, USA) in a future update. In that case the device advertising identifier and usage data may be processed to serve and measure advertising; within the EU, this happens in a restricted mode (no personalised advertising) until consent is obtained. This privacy policy will be updated when advertising is activated, and the Play Store data safety disclosures will be adjusted accordingly.

5. No accounts, no sharing

The app does not require registration. We do not sell personal data and do not share it for advertising purposes. Recipients within the services described above are exclusively Google as processor and provider of the Firebase infrastructure.

6. Your rights

You have the right of access (Art. 15), rectification (Art. 16), erasure (Art. 17), restriction of processing (Art. 18), data portability (Art. 20) and objection (Art. 21 GDPR), and you may lodge a complaint with a supervisory authority. Since puzzle progress is stored purely locally, uninstalling the app deletes it. Requests concerning Firebase data: please use the email address in section 1.

7. Children

The app is not specifically directed at children under 13. We deliberately do not collect personal data from children.

8. Changes to this policy

This policy may be adjusted with app updates (in particular when advertising is activated). The date above is authoritative.