Mathonaut is built to ask as little from you as possible. This policy explains exactly what data the app sends, where it goes, and why.
Mathonaut is developed by Michał Mączka, operating as Bystronaut, a sole-trader software studio based in Switzerland. Contact: mathonaut.app@gmail.com. As the developer, Michał Mączka is the data controller for the purposes of GDPR and equivalent regulations.
Your training sessions, scores, statistics, achievements, settings, and subscription state are stored locally on your device inside the app's sandboxed storage. Uninstalling the app permanently deletes all of it.
If you have iCloud enabled on your device, iOS may sync a subset of your app data (profile totals, streaks, skill scores, settings) to your personal iCloud account under your own Apple ID. This sync happens between your own devices and is governed by Apple's privacy policy. You can disable it at any time in Settings → [your name] → iCloud → Mathonaut.
Mathonaut sends anonymous usage events to our own server (mathonaut-api.bystronaut.com) to help us understand how the app is used and to deliver feature flags. Specifically:
app_opened, session_completed, with the app version and environment. No question content, answers, scores, or personal details are ever sent.All of this data is pseudonymous (no name, email, device name, or IP-linked identity). It is used solely for product analytics and feature delivery. It is not sold or shared with third parties, and is not used for advertising.
Your IP address is visible to our server when the device makes a network request, as is standard for any internet connection. We do not store or log IP addresses beyond what our hosting provider retains for security purposes.
Subscriptions are processed by the Apple App Store or Google Play. We never see your payment details.
To verify and manage subscription state across launches and devices, we use RevenueCat. When you make or restore a purchase, the RevenueCat SDK sends to RevenueCat's servers:
RevenueCat acts as our data processor under a Data Processing Agreement. We do not provide your name, email, or any other personal identifier — we don't have them. See RevenueCat's privacy policy for their full practices.
After your first completed training session, Mathonaut asks for permission to send local practice reminders. If you grant permission, the app schedules reminders entirely on your device. No notification content, timing, or response is ever transmitted to us or to any third party. You can revoke permission at any time in your device's system settings.
Mathonaut Pro subscribers can use the Grade with AI feature to have a completed paper worksheet automatically graded. This feature works as follows:
mathonaut-api.bystronaut.com, together with the list of exercise questions and correct answers for that worksheet.If you do not use the Grade with AI feature, no photos are ever taken or transmitted by the app. On browsers that do not support barcode detection (e.g. Firefox), the upload is still only triggered by the parent's explicit tap — no automatic or background upload occurs.
Onboarding topic detection. During app setup, parents may optionally photograph their child's open math textbook or notebook to automatically identify the current curriculum topic. This feature is part of the Mathonaut subscription (a two-week free trial is offered on first launch). The same technical safeguards apply as for worksheet grading: the action is parent-initiated (explicit tap required), the photo is compressed on-device before upload, and it is processed transiently by AWS Bedrock (Claude) — not stored after the response is returned. Only a cost record (no image, no content) is retained on our servers. The same AWS sub-processor arrangements described above apply. Please take the photo at home of your child's own materials; do not photograph classroom environments or other students' work.
Mathonaut is designed for use by children under parental or guardian supervision. We do not knowingly collect personal information from children within the meaning of COPPA or GDPR. The anonymous analytics described above use a coarse age bracket (set by a parent or guardian in the app) and a random cohort ID — neither constitutes personal information under these laws.
The Grade with AI feature is initiated by a parent or guardian, who photographs a printed paper worksheet. The worksheet contains only math exercises and a barcode — no photographs of children are taken or transmitted. The barcode verification step enforces this on supported browsers. We do not store the worksheet photo; only the grading result and an infrastructure cost record are retained.
The onboarding topic detection feature is likewise initiated by a parent or guardian photographing a math textbook or notebook at home. Parents are instructed not to photograph classroom environments or other students' work. No image data is stored after processing.
Parents and guardians can contact us at mathonaut.app@gmail.com with any questions about data practices for their child's use of the app.
EU and EEA residents: if you believe we have processed personal data of a child under the applicable digital consent age in your member state without proper authorisation, please contact us immediately.
If you are located in the EU, EEA, UK, Switzerland, or another jurisdiction with data protection rights, you may have the right to access, correct, or delete personal data we hold about you. Because the analytics data we collect is pseudonymous and not linked to your identity, we are generally unable to identify or retrieve data for a specific person. To delete all locally stored data, uninstall the app. To cancel a subscription, use your Apple ID subscription settings. For any other requests, email mathonaut.app@gmail.com.
If we change how the app handles data, we will update this page and revise the date at the top.
Questions? Email mathonaut.app@gmail.com.