Legal
Privacy Policy
Last updated: 25 October 2026 · Version 1.0
Chalkwise is a maths notebook with a chalkboard, published by Stichting Le@f. The app works without an account, without advertising and without tracking.
Who is responsible
Stichting Le@f, Ampèrestraat 9, 1976 BE Velsen, the Netherlands (KVK 34140586, VAT NL815590921B01), info@stichtingleaf.nl.
What stays on your device
Your notebooks, pages, chalk strokes, answers and settings are stored locally on your device. They are not uploaded to us and they disappear when you delete the app.
What leaves your device
Only when you scan a problem: the photo you take is compressed and sent to our solver (a Supabase Edge Function in the EU) and from there to a vision model of Anthropic (United States) to read the problem and work out the steps. The result comes back to your device.
Photos are not kept
We do not store your photos. They are processed once to produce the answer and are not saved by us in a database. Our hosting provider may keep short-lived technical logs of the request for security.
What we never collect
- no account, name or e-mail address;
- no device identifier or advertising ID;
- no location;
- no analytics, crash-reporting or tracking SDKs.
Service providers
- Supabase (EU region) — runs the solver.
- Anthropic (United States) — the vision model that reads the sum.
- Apple — App Store, in-app purchases and, if you enable it, device backup.
Purchases
Chalkwise+ is bought through the App Store. Apple handles the payment; we never see your payment details.
Your rights
You can ask us for access, correction or deletion of data about you, and you can object to processing. Write to info@stichtingleaf.nl; we answer within 30 days. You may also complain to the Dutch Data Protection Authority (Autoriteit Persoonsgegevens).
Children
Chalkwise is used by pupils of all ages. Because the app needs no account and stores nothing about you with us, no profile is built — not for adults and not for children.
Changes
We update this policy when the app changes. The version and date above always show the current text.
Contact
Questions about privacy: info@stichtingleaf.nl.