Privacy policy

This policy covers the website chronaut.app, including the launch notification sign-up, and the Chronaut apps — for iPhone, iPad and Mac (section “Chronaut for iPhone, iPad and Mac”) and for Android (section “Chronaut for Android”). It is a translation of the German original; the German version is authoritative. Last updated: 28 September 2026.

Controller

NPI Brandenburg GmbH
Eichspitzweg 5c
14772 Brandenburg an der Havel
Germany
Email: info@npi-brandenburg.de
Phone: +49 (0) 3381 20 82 631

Represented by the managing directors Michael Naumann and Manuel Eckert. Further details in the imprint. No data protection officer has been appointed, as the legal conditions for this are not met; please direct data protection enquiries to the address above.

Hosting

The site is hosted as a static website by ALL-INKL.COM – Neue Medien Münnich, owner René Münnich, Hauptstraße 68, 02742 Friedersdorf, Germany. The host processes data solely on our instructions; the processing is based on a data processing agreement under Art. 28 GDPR.

Server log files

When you open the site, the web server automatically records data transmitted by your browser: IP address, date and time of the request, the requested address (URL), the HTTP status code, the amount of data transferred, the referrer and the user agent (browser and operating system).

The purpose is technical operation, delivery of the site and the prevention and investigation of attacks and abuse. The legal basis is our legitimate interest in a secure, functioning website (Art. 6(1)(f) GDPR). Log files are deleted automatically after 14 days, unless in exceptional cases they are needed for longer to investigate a specific incident of abuse or a security incident. This data is not combined with other sources.

No cookies, no tracking, no external content

This site sets no cookies and uses no analytics, tracking or advertising services. No fonts, scripts, maps, videos or other content are loaded from third-party servers; the typeface is served from our own server. That is why there is no cookie banner. No consent under § 25 TDDDG is required, because nothing beyond what is technically necessary is stored on or read from your device.

Launch notification (double opt-in)

If you would like to hear when Chronaut ships, you can leave an email address on this site. We process:

Sign-up uses double opt-in: after you submit the form we send an email containing a confirmation link. The sign-up only takes effect when you click that link; unconfirmed entries are deleted after 14 days at the latest.

The sole purpose is to tell you about the launch of Chronaut — we write on exactly two occasions: when TestFlight opens and when Chronaut is on the App Store or Google Play. Addresses are never passed on to third parties for advertising.

The legal basis is your consent, Art. 6(1)(a) GDPR. You may withdraw it at any time with effect for the future — via the unsubscribe link contained in every email (/api/unsubscribe.php), or informally by email to us. After withdrawal the address is removed from the list without delay and replaced with a placeholder; only an anonymous record remains, which prevents an unwanted re-send. The list is deleted at the latest once the launch notifications have been sent. Withdrawal does not affect the lawfulness of processing carried out beforehand.

The data is stored in a database on this website’s server; confirmation and notification emails are sent via our hosting provider’s mail server.

Contacting us by email

If you write to us, we process your details in order to handle your enquiry. The legal basis is Art. 6(1)(f) GDPR (our legitimate interest in replying) or Art. 6(1)(b) GDPR where the enquiry relates to a contract or its preparation. We delete the data once the enquiry has been dealt with and no statutory retention obligations apply.

The Chronaut app

The section “Chronaut for iPhone, iPad and Mac” applies to the Apple apps, the section “Chronaut for Android” to the Android app. Both have this in common: there is no server operated by us, and the apps contain no tracking or analytics SDKs.

Chronaut for iPhone, iPad and Mac

Chronaut backs up the calendars on your device, shows which events were deleted, changed or moved, and restores them when you ask it to. Everything it processes for that stays on your device. We receive no calendar data and no other personal data from the app.

What the app processes on the device. With your permission the app reads the calendars and events on the device through Apple’s calendar interface (EventKit). This includes the calendar name, colour and source (e.g. iCloud, Google or Exchange), as well as the title, start and end, time zone, location, notes, recurrence rules, alarms, availability, status and attendees (name, email address, response status) of the events. The app stores these details and their earlier versions in its own database on the device so that it can detect and display changes.

No server, no disclosure. The app sends no calendar data to us or to third parties, contains no advertising, no analytics, tracking or crash-reporting services, and needs no account and no sign-in. In version 1.0 no calendar content leaves the device.

Permissions. The app asks for full access to your calendars. It needs read access because it backs the calendars up, and write access because it can restore events; it only ever writes when you tap “Restore”. You can revoke the permission at any time in the system settings — the app will then tell you that it can no longer back up, and the history already backed up remains readable. For background backups the app uses the iOS task scheduler (BGTaskScheduler); when it runs is decided by the operating system.

Where the data is stored. The database is kept in a protected area of the app on the device (App Group container) that only Chronaut itself can access. If you create a backup of your device via iCloud or a computer in the system settings, the database is part of that backup — Apple is responsible for it, and Apple’s terms and privacy policy apply.

Retention and deletion. The app keeps the backup history for one year and removes older entries automatically; existing events themselves stay backed up. You can remove the entire history at any time in the app’s settings with “Delete all local data”; when you uninstall the app, iOS or macOS deletes all of its data.

Purchases. The full version is sold as a one-time in-app purchase through the App Store. Apple handles the purchase and the payment; Apple gives us no information about you as a person, only aggregated sales figures. The check whether the full version was purchased runs entirely on the device against the App Store receipts — we operate no server for it and query none.

App Store and TestFlight. The app is distributed through the App Store; Apple is responsible for that (Apple Distribution International Ltd., Hollyhill Industrial Estate, Hollyhill, Cork, Ireland), and Apple’s privacy policy applies. In App Store Connect, Apple provides us with aggregated statistics such as download numbers, ratings and — only from devices whose users have consented to sharing with developers — aggregated crash and performance data. None of this allows any conclusions about you. We use it to keep the app stable; the legal basis is our legitimate interest (Art. 6(1)(f) GDPR). Anyone testing via TestFlight additionally sends crash and usage data to Apple and to us; Apple’s TestFlight notices apply to that.

Legal assessment. Because the processing takes place exclusively on your device and we have no access to it, we collect no personal data with the app itself. If your calendars contain information about other people (e.g. attendees), that too stays only on your device.

Children. The app is not directed at children.

Contact and rights. The same contact details and rights described above apply to questions about the app. Because we receive no data about you from the app, we cannot fulfil access or deletion requests regarding the data in the app ourselves — you hold that data entirely on your device and can delete it there at any time.

Chronaut for Android

Chronaut for Android backs up the calendars on your device, shows which events were deleted, changed or moved, and can restore them at your request. Everything the app processes for this stays on your device. We do not receive any calendar data or any other personal data from the app.

What the app processes on the device. With your permission, the app reads the calendars and events on the device through the Android calendar interface. This includes: calendar name, colour and the associated account (e.g. your Google or Exchange address), as well as the title, start and end, time zone, location, notes, recurrence rules, reminders, availability, status and attendees (name, email address, response status) of events. The app stores this information and its earlier versions in its own database on the device so that it can detect and show changes.

No internet, no sharing. The app does not have the permission to access the internet and therefore cannot send any data – neither to us nor to third parties. It contains no advertising, no analytics or tracking services, no crash-reporting services, and it requires no account.

Permissions. The app asks for read access to your calendars (READ_CALENDAR) in order to back them up. The first time you restore an event, it additionally asks for write access (WRITE_CALENDAR); it only writes when you tap “Restore”. When restoring, attendees are not invited again but added to the event’s notes as text. You can revoke both permissions at any time in the Android settings. For background backups the app uses Android’s task scheduler (WorkManager).

Retention and deletion. The app keeps the backup history for one year and removes older entries automatically; events that still exist remain backed up. You can delete the entire history at any time in the app via “Delete all local data”; uninstalling makes Android delete all of the app’s data. The database is excluded from Android backup (Google backup and device-to-device transfer).

Legal classification. Because the processing takes place exclusively on your device and we have no access to it, we do not collect any personal data through the app itself. If your calendars contain information about other people (e.g. attendees), that information also stays on your device only.

Google Play. The app is distributed via Google Play. Google is responsible for downloads and for the use of Google Play (Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland); Google’s privacy policy applies. In the Google Play Console, Google provides us with aggregated statistics, such as install numbers, ratings and – only from devices whose users have agreed to this – aggregated crash and performance data (Android vitals). This information does not allow any conclusions about you. We use it to keep the app stable; the legal basis is our legitimate interest (Art. 6(1)(f) GDPR).

Purchases. The full version is sold as a one-time in-app purchase through Google Play. Google handles the purchase, the payment and your payment details; Google’s privacy policy applies. For each purchase Google provides us with order data in the Play Console (such as order number, date, country and amount), but no payment details and no calendar data; we use it to process the order and for accounting, on the basis of contract performance and our statutory retention obligations (Art. 6(1)(b) and (c) GDPR). Whether the full version was purchased is checked by the app through the Play Store on the device and remembered there — we operate no server for it, and the app needs no internet access of its own.

Children. The app is not directed at children.

Contact and rights. The contact details and rights described above also apply to the app. Because we do not receive any data about you from the app, we cannot ourselves fulfil access or deletion requests regarding the data in the app – you hold this data entirely on your device and can delete it there at any time.

Recipients and transfers to third countries

We pass personal data only to our hosting and mail provider as a processor, and where we are legally obliged to do so. No transfer to countries outside the EU or EEA is intended.

Your rights

Under the GDPR you have the right of access to the data held about you (Art. 15), to rectification (Art. 16), to erasure (Art. 17), to restriction of processing (Art. 18), to data portability (Art. 20), and the right to object to processing based on Art. 6(1)(f) GDPR on grounds relating to your particular situation (Art. 21). You can withdraw consent at any time with effect for the future (Art. 7(3)). Simply contact us at the address above.

Right to lodge a complaint

You also have the right to lodge a complaint with a data protection supervisory authority (Art. 77 GDPR). The authority responsible for us is:

Die Landesbeauftragte für den Datenschutz und für das Recht auf Akteneinsicht Brandenburg
Stahnsdorfer Damm 77
14532 Kleinmachnow
Germany

Obligation to provide data

Providing personal data is neither required by law nor by contract. Without an email address, however, we cannot tell you when Chronaut ships. There is no automated decision-making, including profiling.

Changes to this policy

We update this policy when the website, its features or the legal situation change. The version published here is the one that applies.