Privacy policy

As of 17 October 2026 · provisional version

This English version is a courtesy translation. The German version is the legally binding one.

This privacy policy applies to the website prepguard.de and to the PrepGuard app for iOS and Android. It explains which personal data we process, for what purpose, on what legal basis, who receives it and what rights you have.

1. The most important points in brief

• The app works entirely without an account. Your household, your supplies and your settings then stay on your device only.
• An account is optional. Only with an account do we store your data on our server, so that you can back it up and use it on several devices.
• Warning notifications, crash reports and anonymous usage statistics are only sent with your consent. You can withdraw each of them in the app at any time.
• We only store health information (for example medication) with your explicit consent.
• Our server is in Frankfurt am Main. Some services (Google Firebase, RevenueCat, signing in with Apple or Google) may transfer data to the USA; this is described in detail below.
• The website sets no cookies and uses no tracking and no analytics.

2. Controller

The controller responsible for data processing is:

Barking Cat UG (haftungsbeschränkt)
Am Schwalbenloch 15
76229 Karlsruhe
Germany

Represented by the managing director Patrick Schnoor.
Register court Mannheim, HRB 759821.

Questions about data protection: datenschutz@prepguard.de
General enquiries: support@prepguard.de

You will find further details in the imprint.

3. Data protection officer

We have not appointed a data protection officer. We are not required to, because fewer than 20 people are permanently engaged in processing personal data. For all questions about data protection you can reach us at datenschutz@prepguard.de.

4. The prepguard.de website

4.1 Hosting with GitHub Pages

The website consists of static pages and is delivered through GitHub Pages. The provider is GitHub, Inc., 88 Colin P. Kelly Jr. Street, San Francisco, CA 94107, USA. When you open a page, GitHub processes technically necessary data, in particular your IP address, the date and time, the page requested, the amount of data transferred, and your browser and operating system (server logs). This is needed to deliver the page and to keep the service secure, for example to detect attacks.

The legal basis is Art. 6(1)(f) GDPR. Our legitimate interest lies in providing the website securely and reliably. The data may be transferred to the USA. GitHub is certified under the EU-US Data Privacy Framework; the transfer relies on the European Commission’s adequacy decision. GitHub decides how long it keeps the server logs; we do not analyse them ourselves.

4.2 No cookies, no tracking

The website sets no cookies and stores nothing on your device. We use no analytics, tracking or advertising services. Fonts and all other components are loaded from our own website, not from third-party servers.

4.3 Contact by email

If you write to us by email, we process your email address, your name (if you give it) and the content of your message in order to answer your request. The legal basis is Art. 6(1)(b) GDPR if the request concerns using the app or a subscription, and otherwise Art. 6(1)(f) GDPR (legitimate interest in answering enquiries). We delete the messages once your request has been dealt with and no statutory retention obligations apply.

4.4 Links to other services

This website has only a few links to other services: to Apple’s standard licence agreement in the terms of use, and to the website of the responsible data protection supervisory authority in this privacy policy. Once the app is available in the stores, we will link there as well. These are plain links: you only leave our website when you click one, and the privacy terms of the respective provider apply. No data is transferred to these providers beforehand.

5. The PrepGuard app

5.1 Use without an account: your data stays on your device

You can use PrepGuard entirely without an account. Everything you enter in the app (household, household members, supplies, emergency bag, tasks, settings) is then stored locally on your device only. We have no access to it. Storing it on the device is strictly necessary for the function you asked for (Section 25(2) no. 2 TDDDG).

You delete this data by uninstalling the app. Even if you later sign out of an account, the data stays on the device until you delete it yourself or remove the app.

5.2 Retrieving warnings and basic data

Even without an account, the app retrieves some data from our server (operated by Supabase, see Section 6):

• Current warnings for where you live. For this, the app sends the country and postcode you entered for your household. We do not store this request, neither linked to you nor to your device.
• Basic data for the app, for example recommendations per country, regional risk factors, mappings of products to supply categories and the minimum app version. No information about you is transferred in the process.

With every request, the server technically receives your IP address. It appears in Supabase’s server logs, which serve security and troubleshooting and are deleted automatically after a short time. The legal basis is Art. 6(1)(b) GDPR (providing the functions you use) and, for the logs, Art. 6(1)(f) GDPR (legitimate interest in secure operation).

The warnings themselves come from official sources: for Germany from the federal warning data (BBK, data as in NINA: Modular Warning System MoWaS, German Weather Service, KATWARN, BIWAPP), for Austria and Switzerland from MeteoAlarm (data from GeoSphere Austria and MeteoSwiss respectively). Our server retrieves these sources itself; no data from you is transferred to the sources in the process.

5.3 Warning notifications (push)

If you like, the app notifies you as soon as an authority issues a warning for where you live. This also works without an account. Before you agree, the app shows you which data is transferred for this. Nothing is pre-selected.

If you agree:

• Firebase Cloud Messaging (Google) creates a device identifier (push token) for your device,
• we store this device identifier on our server together with country, postcode and place; if you are signed in, also your user ID,
• the app registers your device with Firebase for the warning area of where you live. The name of this warning area contains country, postcode and place.

When a warning appears for your area, our server sends it through Firebase to all devices registered for that area. The content of the notification is the official warning, not your personal data. In addition, the notification permission of your operating system must have been granted.

The legal basis is your consent under Art. 6(1)(a) GDPR and Section 25(1) TDDDG. Google Ireland Limited or Google LLC may process the data in the USA (see Section 7).

Withdrawal: If you switch warning notifications off in the app (under “Household” → “Manage consents”), the app unregisters your device from all warning areas, and we delete the registration on our server. The app never switches notifications back on by itself afterwards, not even after an update. We automatically delete registrations that have not been updated for six months.

5.4 Location suggestion for postcode and place

When you enter where you live, you can tap the crosshair. The app then asks your operating system once for your current location and suggests the nearest postcode and place. The conversion happens on your device only, using a bundled list of postcode centre points (source: GeoNames, CC BY 4.0). The location coordinates are neither stored nor transferred to us or to third parties. Only the postcode you confirm is stored, just as if you had typed it in. The app never asks for your location in the background.

You grant the location permission in your operating system’s dialogue and can withdraw it there at any time. The legal basis is Art. 6(1)(a) GDPR and Section 25(1) TDDDG.

5.5 Barcode scanner and product search

With the scanner you can record products by their barcode. The app uses your device’s camera for this. The camera image is only evaluated on the device, not stored and not transferred. You grant the camera permission in your operating system’s dialogue.

To find the product name, the app only sends the scanned barcode number to the free product database Open Food Facts (Open Food Facts, France, non-profit). Open Food Facts technically also receives your IP address in the process. The legal basis is Art. 6(1)(f) GDPR; our legitimate interest is simple product recording, which you trigger yourself. The privacy notices of Open Food Facts also apply.

Mapping products to categories: If you are signed in and assign a scanned product to a different supply category, we store this mapping (barcode, country, category) for your household. If at least two households make the same mapping independently, we adopt it into a shared mapping list from which all users benefit. This shared list contains no link to you, your household or your device. The legal basis is Art. 6(1)(b) GDPR for your own mapping and Art. 6(1)(f) GDPR for the shared list (legitimate interest in better product mappings for everyone).

5.6 Account and synchronisation

An account is optional. It lets you back up your data and use it on several devices. You can register with an email address and password or sign in with Apple or Google.

Registration with email: We process your email address and your password (stored only as an encrypted hash). To confirm it, we send you a six-digit code by email, which you enter in the app. You also receive a code to reset your password. A code is valid for one hour. We send the emails through Brevo (Sendinblue GmbH, Berlin). We automatically delete accounts whose email address has not been confirmed within seven days.

Signing in with Apple or Google: You sign in directly with Apple or Google. From there we receive an identifier for your account, your email address (with Apple, on request a forwarding address) and, where applicable, your name. Apple and Google are independently responsible for the sign-in itself; their privacy terms apply. When you sign in with Google, a browser window opens via our server address api.prepguard.de.

What is stored on our server with an account:

• Account data: user ID, email address, sign-in method, times of registration and sign-in;
• Household: name of the household, country, postcode, place, type of home, chosen preparedness period;
• Household members: name or label (freely chosen, for example “Adult 1”), date of birth and age group. This can also concern children; please only enter details about other people if you are entitled to do so;
• Supplies: products, quantities, categories, expiry dates and, where applicable, barcodes;
• Emergency bag, completed tasks, preparedness level, badges, chosen scenarios and product mappings;
• Health information only with separate consent (Section 5.7);
• your consent history (Section 5.12).

The legal basis is Art. 6(1)(b) GDPR, because we need this data to provide you with backup and synchronisation. The data is held by Supabase in a data centre in Frankfurt am Main. Access is technically restricted so that each person can only see the data of their own household. Within our company, only a few authorised people have access, as far as this is needed for operation and support; evaluations for operation are only carried out in aggregate, without reference to individual people.

Signing out: If you sign out, your data stays on the device, and the data on the server also remains until you delete your account.

5.7 Health information

For suitable supplies, you can enter medication (name, how often it is taken, stock), food intolerances and special needs for household members. This is health data and therefore a special category of personal data under Art. 9 GDPR. We only process it with your explicit consent (Art. 9(2)(a) GDPR in conjunction with Art. 6(1)(a) GDPR), which the app asks for before the first entry, and only to tailor your supplies and your preparedness. Without an account, the information stays on your device; with an account it is stored in Frankfurt like the rest of the household data.

Withdrawal: If you withdraw this consent under “Household” → “Manage consents”, the app, after asking you to confirm, deletes the health information of all household members, on the device and on the server. If the device is offline, the deletion on the server is carried out as soon as a connection is available again.

5.8 Premium subscription

Some additional features are available with the Premium subscription. It is bought and paid for exclusively through Apple’s App Store or Google Play. We do not receive payment details; Apple or Google process these under their own responsibility.

To check whether a subscription exists, we use the service RevenueCat (RevenueCat, Inc., USA). For this, the app asks RevenueCat for the subscription status at start-up. RevenueCat processes an app user ID (with an account your user ID with us, without an account a random ID), purchase and receipt data from the store (product, purchase date, term, store), the platform, the app version and, technically, your IP address. The app stores the subscription status on your device so that Premium also works offline. We do not store the subscription status on our own server.

The legal basis is Art. 6(1)(b) GDPR (providing the subscription) and, for the status query without an intention to buy, Art. 6(1)(f) GDPR (legitimate interest in unlocking the right features). RevenueCat processes the data in the USA (see Section 7).

5.9 Crash reports and anonymous usage statistics

Only if you consent (“Send anonymous usage and crash reports”) do we process:

• Crash reports through Firebase Crashlytics (Google): technical error history, device model, operating system, app version and a random installation ID. The app is built so that reports contain no names, supply contents or location data. The purpose is to find and fix errors.
• Anonymous daily counters on our server: how often scanned products of a category could be mapped, which routes are used to record, remove, delete or undo supplies, and whether warning notifications arrived in a warning area. Only “day, country, measure, count” is stored; for delivery confirmation, the warning area (postcode and place) is part of the measure. The counters contain no identifier of you, your household or your device, no product names and no barcodes. They are only sent if you are signed in.

The legal basis is your consent under Art. 6(1)(a) GDPR and Section 25(1) TDDDG. Google may process Crashlytics data in the USA (see Section 7).

Withdrawal: Under “Household” → “Manage consents”. After that, the app sends no crash reports and no counters any more; values that have already been counted but not yet sent stay unsent on the device.

5.10 Reminders

The app schedules reminders about expiry dates and about checking your supplies locally on your device. No data is transferred to us or to third parties for this.

5.11 Product links (affiliate links)

For some gaps in your supplies, the app shows a link marked “affiliate link”, “Buy online”, to Amazon. Only when you tap it does the Amazon page (amazon.de) open in your browser. Amazon then receives the usual connection data (for example your IP address) and a partner ID, through which we may receive a commission on a purchase. We do not learn who clicked or bought. Amazon is responsible for processing on the Amazon page. The legal basis for showing the link is Art. 6(1)(f) GDPR (legitimate interest in funding the free basic features).

5.12 Proof of your consents

We have to be able to prove that you consented. If you are signed in, we therefore store an entry for every grant and every withdrawal, with the type of consent, granted or withdrawn, the version of the text and the time. These entries cannot be changed afterwards. The legal basis is Art. 6(1)(c) GDPR in conjunction with Art. 7(1) GDPR. Without an account, your decision is only stored on the device.

5.13 Downloading the app

When you download the app from the App Store or Google Play, Apple or Google process data such as your store account and device data for this, under their own responsibility. We have no influence on that.

6. Recipients and processors

We only pass on your data as far as this is necessary for the purposes described. Service providers who work on our behalf (processors) are bound by contract to our instructions and to the GDPR.

7. Transfers to countries outside the EU

We store your account data and household data in the EU (Frankfurt am Main). Some service providers are based in the USA or may process data there: Google (Firebase Cloud Messaging, Crashlytics, signing in with Google), Apple (signing in with Apple), RevenueCat, Amazon after a click on an affiliate link, GitHub for the website, and Supabase for possible administrative access by its US parent company.

For the USA, the European Commission has adopted an adequacy decision for companies certified under the EU-US Data Privacy Framework (Art. 45 GDPR). Where a recipient is not certified, we base the transfer on the European Commission’s standard contractual clauses (Art. 46(2)(c) GDPR). You can request a copy of the standard contractual clauses from us.

8. How long we store data

• Data only on your device: until you delete it in the app or uninstall the app.
• Account and household data on the server: until you delete your account.
• Unconfirmed accounts: seven days after registration.
• Health information: until you delete it, withdraw your consent or delete your account.
• Push registration: until you switch warning notifications off or delete your account, six months after the last update at the latest.
• Consent history: until you delete your account.
• Crash reports at Crashlytics: according to Google’s rules, currently 90 days.
• Server logs with IP address: only briefly, according to the rules of the respective service.
• Anonymous daily counters and the shared product mapping: contain no personal data and are therefore not stored as personal data.

Statutory retention obligations, for example for business correspondence, remain unaffected.

9. Withdrawing consents

You can withdraw any consent at any time with effect for the future, just as easily as you gave it. In the app you will find all consents with their status and date under “Household” → “Manage consents”:

• Warning notifications: unregistering from all warning areas and deleting the registration on our server (Section 5.3).
• Crash reports and usage statistics: nothing is sent any more (Section 5.9).
• Health information: deleting the health information of all household members on the device and the server (Section 5.7).
• Location and camera: in your operating system’s settings.

Agreeing to the terms of use and to data processing at registration belongs to the account; you end it by deleting your account. The lawfulness of processing up to the withdrawal remains unaffected.

10. Deleting your account

You can delete your account in the app at any time: under “Household” (household icon) → “Account” section → “Delete account”. In doing so, we delete your account and all data linked to it on our server (household, members, supplies, health information, consent history, push registration) as well as the app’s data on the device. The deletion cannot be undone.

If you no longer have the app installed, you can also request the deletion on the Delete account page.

Important: Deleting your account does not cancel a Premium subscription. You cancel subscriptions in the subscription settings of the App Store or Google Play. Purchase data at Apple, Google and RevenueCat is not deleted automatically; we delete the data at RevenueCat on request to datenschutz@prepguard.de, as long as no statutory retention obligations stand in the way.

11. Your rights

Under the GDPR you have the following rights:

• Access to the data we process about you (Art. 15 GDPR). With an account, you can retrieve your data as a file yourself in the app under “Household” → “Account” section → “Export my data”.
• Rectification of incorrect data (Art. 16 GDPR). You can change most details in the app yourself.
• Erasure of your data (Art. 17 GDPR), see Section 10.
• Restriction of processing (Art. 18 GDPR).
• Data portability (Art. 20 GDPR): the export provides your data in a common, machine-readable format (JSON).
• Objection to processing based on our legitimate interest (Art. 21 GDPR), on grounds relating to your particular situation.
• Withdrawal of consents you have given (Art. 7(3) GDPR), see Section 9.

An email to datenschutz@prepguard.de is enough for any request. Without an account, your app data is only on your device; we can then neither see it nor hand it over.

Complaint to a supervisory authority (Art. 77 GDPR): You can complain to a data protection supervisory authority. The authority responsible for us is the State Commissioner for Data Protection and Freedom of Information Baden-Württemberg (Der Landesbeauftragte für den Datenschutz und die Informationsfreiheit Baden-Württemberg), Lautenschlagerstraße 20, 70173 Stuttgart, www.baden-wuerttemberg.datenschutz.de. In Austria you can also turn to the Datenschutzbehörde, in Switzerland to the Federal Data Protection and Information Commissioner (FDPIC).

12. Obligation to provide data and automated decisions

You are not obliged to provide us with data. Without an account, you can use the app in full. For an account we need your email address or a sign-in through Apple or Google; for warnings about where you live we need the postcode. Without this information, only these features are unavailable.

The preparedness level, recommendations and hints in the app are calculated by fixed rules. There is no automated decision within the meaning of Art. 22 GDPR that has legal effect on you.

13. Security

All connections between the app, the website and the servers are encrypted (TLS). The app stores your sign-in session in your device’s protected storage (Keychain or Keystore). On the server, access at data level is restricted so that each person can only read and change the data of their own household.

14. Changes to this privacy policy

We adjust this privacy policy when the app, our service providers or the law change. The version published here at the time applies. We will tell you about significant changes in the app.

See also: Terms of use · Imprint · Support