These apps are designed to respect your privacy. We do not require an account, and we do not collect, sell, or share personal information.
The only information saved is your practice log — how many repetitions and how much time you've spent on each exercise. This is stored on your own device using your browser's local storage. It never leaves your device and is not transmitted to us or anyone else. You may download it as a file to share with your teacher if you choose, and you can clear it at any time with the in-app Reset or by clearing your browser data.
No name, no email, no account, no location, no advertising identifiers. We do not use your microphone or camera. We currently run no advertising and no third-party behavioural tracking.
To display correctly, the app loads fonts from Google Fonts and a music-notation library from a public content-delivery network (jsDelivr). When your browser requests these files, those providers may receive standard technical information such as your IP address, as described in their own privacy policies. We do not control and are not responsible for those services.
If we add privacy-respecting, anonymous usage analytics in the future, this page will be updated to say so before it goes live.
These apps are suitable for learners of all ages, including children, and are appropriate for use under a teacher's or parent's guidance. Because the apps collect no personal information from anyone — no name, email, account, location, microphone, camera, or advertising identifiers — and store only your practice log locally on your own device, they do not knowingly collect personal information from children under 13 (US Children's Online Privacy Protection Act, COPPA) or under 16 (EU GDPR-K). No registration or parental-consent flow is required, because no personal data is collected. Parents and teachers with any question can reach us below.
Questions? Reach the creator, Prof. Thomas Hornig, at tomhornig.blog.