MondstundePrivacy policy
Mondstunde app and website · Last updated: 15 October 2026 · The German version is legally binding.
In short
- You don't need an account. The app signs in with a random, anonymous ID.
- For a story we only send your child's first name, age and form of address, the options you chose and the names of other characters. For reading aloud, the text of the story is added.
- Stories and audio are stored only on your device, not on our servers.
- The AI (Google Gemini) does not use your input for training.
- Anonymous usage statistics are collected only with your consent. You can turn them off in Settings at any time.
- No ads, no tracking across other apps, no selling of data.
1. Controller
Christian Kau
Brunnenstraße 121
53332 Bornheim
Germany
Email: datenschutz@mondstunde.com
No data protection officer has been appointed, as there is no legal obligation to do so.
2. Who the app is for
Mondstunde is meant for parents and other adults who read stories to children. You enter the details about the child (first name, age, form of address) as an adult. Please don't enter sensitive information such as health details, surnames or addresses in free-text fields (e.g. your own theme, your own goal or names of siblings, friends and cuddly toys). They are not needed for the story.
3. Anonymous sign-in
When you create your first story, the app automatically creates a random ID with our backend provider Supabase. It contains no name, no email address and no phone number. The credentials for this ID are stored securely in your device's keychain.
With every request, the server processes your IP address and the time and type of request for technical reasons (server logs). These logs serve secure operation and are deleted after 7 days at most.
Legal basis: Art. 6(1)(b) GDPR (providing the app); for logs Art. 6(1)(f) GDPR (legitimate interest in security and abuse prevention). Storing the credentials on the device: § 25(2) no. 2 TDDDG (strictly necessary).
4. Creating stories
When you create a story or a continuation, the app sends the following to our server:
- the child's first name, age and form of address ("girl", "boy" or "name only")
- the chosen world, goal, sub-topic, length, language level and any text you entered for them
- names of other characters you enter (e.g. siblings, friends, cuddly toys) and whether your child appears in the story
- for continuations: the previous story and the chosen direction
Our server forwards this information to the AI Google Gemini, which writes the story and checks it for child-appropriate content. The finished story is returned to the app. We store neither your input nor the story on our server.
According to its terms, Google does not use requests to the paid Gemini service to improve its own products or to train AI models. Google keeps requests and responses only for a limited time to detect abuse and meet legal obligations. Processing is based on Google's data processing agreement.
Legal basis: Art. 6(1)(b) GDPR (creating the story you requested).
Note: the stories are generated by AI. Despite the checks they may contain mistakes.
5. Reading aloud with the AI voice
To read a story aloud with the AI voice, the app sends the text of the story section by section via our server to Google Gemini, together with the chosen voice. The generated audio is returned to the app and stored only on your device. So that "Listen" starts right away, the beginning is voiced right after a story is created if you chose "AI voice". With "Read it yourself" this only happens when you explicitly ask for it.
Our server only voices texts it generated itself. For this, every paragraph gets a cryptographic signature that contains no personal data.
Alternatively, stories can be read aloud with the iOS device voice. This happens entirely on your device.
Legal basis: Art. 6(1)(b) GDPR.
6. Usage allowance
To provide the free story and the subscription allowances and to prevent abuse, we store only two numbers per week for your anonymous ID: how many stories were created and how many seconds were read aloud. No content or names are stored. The app shows your current balance in Settings.
Legal basis: Art. 6(1)(b) and (f) GDPR.
7. Data on your device
Child profiles, stories, favorites, voiced audio and your settings are stored only in the app on your device. They are included in your device backup (e.g. iCloud Backup) if you use it. Deleting the app removes them.
The bedtime reminder is a local notification on your device. No data is sent to us for it.
8. Anonymous usage statistics (only with consent)
If you agree, we send anonymous usage signals to TelemetryDeck (TelemetryDeck GmbH, Germany). Examples: "onboarding step viewed", "story created" (with world, goal and length), "story listened to the end", "subscription page shown". This shows us which features are used and where the app needs improvement.
No names, no texts and no story content are transmitted. TelemetryDeck does not store IP addresses and only receives a hashed device ID that cannot be traced back to you.
You can withdraw your consent at any time in the app under Settings → Privacy → Share anonymous usage statistics. After that, no more signals are sent.
Legal basis: Art. 6(1)(a) GDPR and § 25(1) TDDDG (consent).
9. Subscriptions
Subscriptions are purchased and billed exclusively through Apple's App Store. Only Apple processes payment and account data. To unlock your subscription in the app, our server verifies the purchase with Apple and stores, linked to your anonymous ID: Apple's transaction number of the subscription, the product (Family or Basic), the expiry date and whether it is a test purchase. We never receive your name, Apple ID or payment details. Apple's privacy policy applies to the purchase itself.
Legal basis: Art. 6(1)(b) GDPR.
10. Contacting us by email or contact form
If you write to hallo@mondstunde.com or datenschutz@mondstunde.com, we process your email address, your name (if given) and the content of your message to reply to you. Our email provider INWX (INWX GmbH, Berlin) receives the messages and forwards them to our mailbox at Google (Gmail), where we read and answer them. We delete messages 2 years after your request has been completed, unless statutory retention obligations apply.
Through the contact form on this website we receive your email address, your name (optional), your message and the language of the page. This is stored with our backend provider Supabase (data center in Frankfurt am Main), and only we have access. Messages are not forwarded automatically by email. We delete the message 2 years after it arrives. When you submit, the server technically processes your IP address (server logs, at most 7 days, see section 3).
Legal basis: Art. 6(1)(b) GDPR (questions about the app or subscription) or Art. 6(1)(f) GDPR (legitimate interest in answering requests); for requests about your data protection rights, Art. 6(1)(c) GDPR.
11. Recipients and processors
| Provider | Purpose | Place of processing |
|---|---|---|
| Supabase Pte. Ltd. (Singapore) | Server, anonymous sign-in, usage counters, subscription status, contact form | Data center in Frankfurt am Main (EU) |
| Google (Gemini API) | AI for text and voice (Gemini) | EU and other countries where Google operates data centers |
| TelemetryDeck GmbH (Germany) | Anonymous usage statistics, only with consent | EU |
| GitHub, Inc. (USA) | Hosting this website (GitHub Pages) | USA and other countries |
| Apple (App Store) | Download, subscriptions, payment | see Apple's privacy policy |
| INWX GmbH (Germany) | Receiving and forwarding email, domain | Germany |
| Google (Gmail) | Email mailbox | EU and other countries where Google operates data centers |
Supabase, Google (Gemini API), TelemetryDeck and INWX process the data on our behalf under Art. 28 GDPR. Google's terms and privacy policy apply to Gmail.
12. Transfers outside the EU
Our backend provider Supabase Pte. Ltd. is based in Singapore; the data is stored in a data center in Frankfurt am Main. Google and GitHub are headquartered in the USA. Access from or processing in Singapore or the USA, including by sub-processors, therefore cannot be ruled out. For Supabase, the EU standard contractual clauses (Art. 46(2)(c) GDPR) apply as part of the data processing agreement. For Google and GitHub, this is based on the European Commission's adequacy decision for the EU-US Data Privacy Framework where the provider is certified, and otherwise also on the EU standard contractual clauses.
13. Storage periods
| Data | How long |
|---|---|
| Input for a story, text for reading aloud | not stored on our server; at Google only briefly for abuse detection |
| Server logs (incl. IP address) | 7 days at most |
| Weekly usage counters | 13 weeks, then deleted automatically |
| Anonymous ID | until 6 months after last use, then deleted automatically |
| Subscription status (transaction number, product, expiry date) | together with the anonymous ID, i.e. at most 6 months after last use |
| Emails to us | 2 years after the request has been completed |
| Messages from the contact form | 2 years after they arrive, then deleted automatically |
| Stories, audio and profiles on your device | until you delete them or the app |
| Usage statistics (TelemetryDeck) | anonymous, per TelemetryDeck's retention periods |
14. Your rights
You have the right to
- access your stored data (Art. 15 GDPR),
- rectification (Art. 16 GDPR) and erasure (Art. 17 GDPR),
- restriction of processing (Art. 18 GDPR) and data portability (Art. 20 GDPR),
- object to processing based on legitimate interests (Art. 21 GDPR),
- withdraw consent with effect for the future (Art. 7(3) GDPR).
Since we don't know you by name, most data is stored only on your device, where you can delete it at any time. For questions and requests, write to datenschutz@mondstunde.com.
You can also lodge a complaint with a data protection supervisory authority, e.g. the State Commissioner for Data Protection and Freedom of Information of North Rhine-Westphalia (LDI NRW), Kavalleriestraße 2–4, 40213 Düsseldorf, Germany, www.ldi.nrw.de.
15. This website
The website mondstunde.com is stored and delivered by GitHub Pages (GitHub, Inc., USA). When you visit, GitHub processes your IP address, the time, the requested page and information about your browser and operating system in server logs for technical reasons, to deliver the site and protect it against attacks.
The website sets no cookies, uses no analytics or tracking services and loads no fonts or content from other servers.
Legal basis: Art. 6(1)(f) GDPR (legitimate interest in providing the website securely and reliably). Transfer to the USA based on the EU-US Data Privacy Framework or standard contractual clauses.
16. Changes
As we develop the app further, we update this policy. The current version is always available on this page and in the app.