Updated August 4, 2026
This policy explains what data the VivreEnsemblePrep mobile app and the website vivre-ensemble-prep.luxify.lu collect, why, on what legal basis and for how long. It is written in accordance with the General Data Protection Regulation (GDPR, EU Regulation 2016/679) and the Luxembourg law of 1 August 2018.
The data controller is Julien Kessels, publisher of the VivreEnsemblePrep app and of the website vivre-ensemble-prep.luxify.lu.
For any question about your personal data, or to exercise your rights, write to privacy@luxify.lu. We reply within one month at the latest, in line with Article 12 GDPR.
The app is designed to work without identification. We collect no name, no address, no date of birth and no data relating to your nationality application.
Your answers, your accuracy per subject, your mock exam scores and your preferences (language, home screen layout, onboarding status) are stored in your device's local storage, using the operating system's standard storage mechanism.
This information never leaves your phone. We have no access to it. It is permanently deleted when you reset your progress from the app settings, or when you uninstall the app.
The app includes Google Firebase Analytics so we can understand how it is used: screens viewed, features triggered, interface language, device type, operating system version and app version. These events are tied to a pseudonymous installation identifier generated by Firebase, not to your identity.
On iOS, the app is configured without advertising identifier (IDFA) support: we collect no identifier for advertising purposes, and the app shows no advertising.
Purpose: improving the app and fixing journeys that cause problems. Legal basis: our legitimate interest in improving a service you chose to install (Article 6(1)(f) GDPR). You can object at any time by turning off analytics sharing in your device settings, or by writing to us.
Google acts as a processor. Transfers outside the European Union may occur; they are covered by the European Commission's standard contractual clauses and by the EU–US Data Privacy Framework.
We include no third-party crash reporting tool in the app. If you have agreed to share analytics and diagnostic data with developers in your Apple device settings, Apple may pass us aggregated, anonymised crash reports through App Store Connect. These reports contain technical information (device model, system version, stack trace) and cannot identify you.
You can turn this sharing off at any time in Settings › Privacy & Security › Analytics & Improvements.
Purchases are made through Apple's App Store. Apple processes the payment, and we never receive your card number, your billing address or your Apple ID.
We use RevenueCat, a provider specialising in mobile subscription management, to verify that your purchase is valid and unlock Premium features. RevenueCat processes an anonymous app identifier, the identifier of the product purchased, the purchase date, the expiry date and the store country. None of this data identifies you by name.
Purpose: performing the contract entered into when you take out a subscription. Legal basis: performance of a contract (Article 6(1)(b) GDPR).
If you accept them, the app schedules daily revision reminders. These notifications are generated and scheduled locally on your device: they pass through no server and we collect no push notification token.
You can decline them on first launch or turn them off at any time in your device settings. Legal basis: your consent (Article 6(1)(a) GDPR).
The website vivre-ensemble-prep.luxify.lu is a static site. It includes no analytics tool, no advertising pixel, no tracking social button and no third-party script.
The site sets a single cookie, named NEXT_LOCALE. It remembers the language you chose so you are sent to the right version of the site on later visits. It contains no personal identifier, does not track your browsing and is never shared.
This cookie is strictly necessary for the site's multilingual operation and falls under the consent exemption provided for by the ePrivacy Directive. That is why you are not shown a consent banner.
You can delete it at any time through your browser settings; the site will keep working and will show the language detected by your browser.
The exam simulator on this site runs entirely in your browser. Your answers, your score and your time are sent to no server and are kept nowhere once you close the tab.
The site is hosted by Vercel Inc. Like any host, Vercel records technical logs containing the connecting IP address, the date, the page requested and the browser type. These logs are used solely to keep the service secure and available, and are retained for a limited period set by the host.
Legal basis: our legitimate interest in protecting the service against abuse and attack (Article 6(1)(f) GDPR).
When you write to us, we process your email address and the content of your message for the sole purpose of replying. These exchanges are kept for a maximum of twenty-four months, then deleted.
We never use your address to send you a newsletter or a commercial offer, and we pass it to nobody.
Legal basis: our legitimate interest in answering the requests sent to us (Article 6(1)(f) GDPR).
Progress and preferences in the app: kept on your device until reset or uninstall, with no limit on our side since we have no access to them.
Firebase analytics events: kept for the period configured in Firebase, up to fourteen months.
Subscription data at RevenueCat: kept for the duration of the contractual relationship, then for as long as needed to meet our accounting and tax obligations.
Hosting logs: a limited period set by the host, generally a few weeks.
Correspondence: twenty-four months maximum.
We do not sell, rent or trade any personal data. The only third parties that may process data on our behalf are:
Each of these providers acts as a processor or as an independent controller depending on the case, under appropriate contractual safeguards. We may also have to disclose information where the law requires it.
The GDPR gives you the following rights over your personal data:
To exercise these rights, write to privacy@luxify.lu. Because the app has no user account, we may ask you for details identifying the installation concerned, for example your Firebase installation identifier.
If you believe your rights are not being respected, you can lodge a complaint with the Commission nationale pour la protection des données (CNPD) in Luxembourg, or with the supervisory authority of your country of residence.
To erase your progress: open the app settings and choose “Reset progress”. The deletion is immediate and permanent. Uninstalling the app also removes all local data.
To erase your analytics data: write to privacy@luxify.lu with your Firebase installation identifier, available from the app's developer settings. We forward the deletion request to Firebase.
To erase your subscription data: write to us. Some information must nonetheless be kept to meet our accounting and tax obligations, and Apple's billing requirements.
The app is aimed at adults engaged in an application for Luxembourg nationality. It is not intended for children under sixteen and we do not knowingly collect data about them.
Exchanges with the site and with our providers are encrypted in transit (HTTPS/TLS). Progress data stays on your device and benefits from the operating system's encryption when that is enabled.
No system is infallible. In the event of a data breach likely to result in a high risk to your rights, we would notify the CNPD within 72 hours and the individuals concerned as soon as possible, in line with Articles 33 and 34 GDPR.
We may amend this policy to reflect changes in the app, our providers or the law. The date of the last update appears at the top of this page. In the event of a substantial change, the information will be shown in the app.