Privacy Policy

Last updated: September 2026

This privacy policy applies to the app Ixilotl.

Data controller

The data controller within the meaning of the General Data Protection Regulation (GDPR) is:
Sebastian Buhl
Rheingoldstr. 5
65203 Wiesbaden
Germany
Email: ixilotl.app@gmail.com

What data is stored?

Ixilotl stores local game data on the device (learning progress, settings). This data never leaves the device and is not shared with third parties.

The app additionally uses Firebase Crashlytics and Firebase Analytics (see below). There is no user account and no chat feature. The app shows no advertising – neither personalized nor of any other kind.

Crash and usage data (Firebase Crashlytics & Analytics)

The app uses Firebase Crashlytics and Firebase Analytics (Google LLC) to detect crashes and understand how the app is used, so we can improve it. This may transmit the following information:

Device model, operating system version, coarse location region (country/city, derived from IP address, not precise)
Timing and stack traces of crashes
App usage events (e.g. which areas of the app are opened), without real names or contact details

This data is not linked to a user account (there is none) and contains no information that allows direct identification of a person. There is no personalized advertising and the device's advertising ID is not used for this purpose.

This data collection is active by default but can be turned off at any time in the app's settings via the "Send anonymous usage & crash data" toggle.
More information: firebase.google.com/support/privacy

Legal basis

Processing of crash and usage data is based on our legitimate interest (Art. 6(1)(f) GDPR) in fixing bugs, ensuring stability, and improving the app. Since this collection is active by default, you have the right to object at any time via the toggle described above.

International data transfers

Firebase Crashlytics and Firebase Analytics are provided by Google LLC and/or Google Ireland Limited. Data may be transferred to the USA or other third countries as part of this. Google states that it relies on the EU Standard Contractual Clauses as an appropriate safeguard within the meaning of Art. 46 GDPR. Details: firebase.google.com/support/privacy.

Retention period

Local game data remains on the device until the app is uninstalled or progress is reset. The retention period for Crashlytics/Analytics data processed by Google is determined by Google under its own Firebase product retention policies; we do not set these periods ourselves.

Your rights

You have the following rights regarding your personal data vis-à-vis the data controller:

Right of access (Art. 15 GDPR)
Right to rectification (Art. 16 GDPR)
Right to erasure (Art. 17 GDPR)
Right to restriction of processing (Art. 18 GDPR)
Right to data portability (Art. 20 GDPR)
Right to object to processing (Art. 21 GDPR)

Since learning progress is stored exclusively locally on the device, these rights in practice mainly concern the crash/usage data collected via Firebase. You also have the right to lodge a complaint with a data protection supervisory authority (Art. 77 GDPR) — typically the authority in your country or state of residence. For Hesse (Germany), this is the Hessischer Beauftragter für Datenschutz und Informationsfreiheit.

Children

Ixilotl is aimed at primary-school-age children. The app does not collect personal data that would allow identification of a child. There is no chat feature, no social networks, and no advertising. Parents can disable the usage-data collection described above at any time in the app's settings.

In-app purchases

The app offers a one-time purchase through the Google Play Store. Payment processing and the associated data handling are subject to Google's privacy policy.

Contact

For privacy-related questions:
Sebastian Buhl
ixilotl.app@gmail.com