Math Compendium privacy

Updated 14 October 2026.

The app stores your chosen name, learning path, settings, answers counted, recent question fingerprints used to vary practice, topic mastery, concept checks tried, your journey starting point, introductions and explored topics, revision topics, XP, badges, daily results, and any handwritten or typed study notes you choose to save locally on your device. Unfinished writing may also be kept locally as a recovery draft when storage is available. There is no app account, cloud sync, purchase or subscription service. Your learning profile, note contents and handwriting are not sent to an advertising service.

The Android and iOS mobile apps integrate Google AdMob and Google's User Messaging Platform for advertising and privacy choices. Development builds use Google's test ads; the browser version does not request AdMob ads. Before requesting ads, the app checks the applicable SDK consent status. The current integration uses conservative child-directed, under-age and general-audience content settings, requests non-personalised inventory where supported, removes the Android advertising-ID permission and does not request Apple's tracking permission. These settings do not mean the advertising SDK processes no data.

Google's advertising SDK may process IP address and approximate location inferred from it, app/device information and permitted app-scoped identifiers, ad views and interactions, and diagnostic/performance data for advertising, measurement and fraud prevention. Actual processing depends on platform, SDK settings and your privacy choices. See Google's privacy policy and its Android and iOS SDK data disclosures. Settings → Advertising & privacy provides the SDK's privacy-options form where applicable.

The learner's broad age group, ad-frequency counters and earned ad-free time are saved locally. School level does not determine age. If age is not shared, the app uses the conservative setting. Full-screen and rewarded ads are limited to self-declared adult learners. Younger and unknown-age learners may receive suitable banners at designated Home/results placements, after the protected first learning session. No ad appears within questions, introductions or notes. A rewarded ad grants 30 active minutes without ordinary ads only when the SDK confirms the reward; the remaining time pauses in the background and is saved separately from game progress.

Settings offers an optional device playtest report for grown-ups testing the game. Recording is off by default. When enabled, it keeps aggregate round counts, answer and hint counts, active play time and first-answer timing locally, with at most 31 daily summaries. It does not record names, identifiers, question text, note contents or handwriting, and sends nothing to a server. You can stop recording, clear the report, or explicitly export it as a JSON file. Sharing an exported report through another app only happens when you choose a destination.

Your name is optional. Please avoid entering sensitive personal information. Use Settings → Reset all progress to erase game progress from this device. Study notes and recovery drafts are kept separately; open Notes to edit or delete individual saved notes. Discard unfinished changes, or choose Keep current on a recovery prompt, to remove that recovery draft. Clearing browser storage or uninstalling may also remove progress, notes and drafts, depending on platform backup settings.

The app caches its files for offline play after a full online load. Your hosting provider may receive normal requests when you load the website. Your learning profile, study notes and recovery drafts stay on the device; mobile advertising communicates separately with Google's services as described above. The app does not request notification permissions.

Sharing is optional and only happens when you tap Share my progress. It shares the achievement text you see, without your name or detailed answers.

Backup & restore exports a JSON file containing your saved notes, handwriting and question references. Unfinished drafts are not included. Importing a backup reads the selected file locally and keeps your existing notes if versions conflict. A browser download or the native system share sheet lets you choose where to keep the backup. Importing does not upload it; sharing through another app only happens when you choose that destination.

Early learners may need a grown-up to read questions aloud. This privacy description applies to version 0.1.0; future cloud or classroom features would need an updated policy.