App privacy policy

Last updated: 22 August 2026

Mr. Grummel ("the app", "we" — during development also called LearnBlocker) is a focus and learning app that asks you quiz questions before you open apps you've chosen to limit. This policy explains what data the app handles and why. We keep it short because we collect very little.

1. Who is responsible

The controller for the data described here, within the meaning of Art. 4(7) GDPR, is:

Full contact details are in the imprint. We are based in Switzerland, so the Swiss Federal Act on Data Protection (revFADP) governs everything described here. We apply the GDPR's standards to everybody, wherever you happen to live. Where the two regimes differ, we apply whichever gives you more.

2. What the app collects

Account data. You can use the app without providing any personal information: by default it creates an anonymous account (a random identifier) so your progress can be saved. If you choose to create a full account, we store your email address. If you set a display name or avatar in your profile, those stay on your device only.

Learning activity. To power streaks, statistics, and reviews, we store which quiz questions you answered, whether you answered correctly, and when. This is linked to your (possibly anonymous) account identifier.

Preferences. Your chosen subjects, difficulty, blocked-app selections, and sound settings are stored on your device. Subject enrolments are also synced to your account so questions can be served to you.

Subject requests and votes. If you request a subject or vote on requests, we store the request text and your vote, linked to your account.

Usage analytics. To understand where people get stuck, we record which screens you viewed and which buttons you tapped — for example that you reached step 8 of setup, or dismissed the subscription screen. These events carry your (possibly anonymous) account identifier and simple counts, never your display name, email address, subject names, or answer content. You can turn this off at any time: Settings → Share usage data.

3. What we deliberately do NOT collect

• No advertising identifiers, no ad networks, no tracking across other apps.
• No sale or sharing of personal data with third parties for their own use.
• No contacts, location, photos, or browsing history.
• Your blocked-app selections are used only on your device to decide when to show you a quiz.

4. Who else processes your data

We use a small number of service providers, each acting as a processor under Art. 28 GDPR and permitted to use your data only to provide the service we engaged them for:

• Database and authentication — Supabase, storing account and learning data on our behalf. Region: European Union.
• Usage analytics — PostHog, processing the events described in section 2 on our behalf, on their EU servers.
• Purchases — payments are handled by Apple's App Store / Google Play under their own terms, and subscription status by RevenueCat. We never see your payment details.

We do not sell your data, and we do not share it with anyone outside this list.

5. AI-assisted content

Some quiz questions and curriculum content are drafted with the help of AI tools (such as Anthropic's Claude) and reviewed before being published in the app. This happens during development only: the app does not send your personal data, your answers, or anything else about you to any AI provider.

6. Children

The app is a general-audience, self-directed focus tool. It is not directed at children under 13, and we do not knowingly collect personal information from them. If you believe a child has given us personal data, write to the address in section 1 and we will delete it.

7. Your rights: access and deletion

You can stop usage analytics at any time in the app: Settings → Share usage data. Turning it off takes effect immediately and no further events are sent.

You can delete your account and all associated data at any time in the app: Settings → Profile → Delete Account. Deletion permanently erases your account, answer history, streaks, enrolments, and settings from our servers. Subject requests you submitted remain (they are community content) but are anonymized — the link to your account is removed.

Beyond that, under the GDPR you have the right to access the data we hold about you (Art. 15), have inaccurate data corrected (Art. 16), have it erased (Art. 17), restrict processing (Art. 18), receive it in a portable format (Art. 20), object to processing based on legitimate interest (Art. 21), and withdraw consent at any time (Art. 7(3)). Under the revFADP you additionally have the Swiss-law rights of access and correction. Write to the address in section 1 and we will deal with it — free of charge, and normally within a month.

You also have the right to complain to a supervisory authority. Ours is the Federal Data Protection and Information Commissioner (FDPIC / EDÖB), Feldeggweg 1, 3003 Bern. If you are in the EU, you may instead complain to the data protection authority of the country where you live or work.

8. Changes

If this policy changes materially, we will update the date above and note the change in the app or release notes.