Privacy Policy
Last updated: November 2026
Zero & One is a free study app for the Programming & Artificial Intelligence course. You can use all of it without an account.
- Without signing in: your progress, scores, mistakes and written answers are stored on your device only.
- Teacher challenges: when you solve a challenge sent by your teacher, the name you type, your score, time and the questions you missed are sent to the app server and shown only to the teacher who created that challenge. A teacher's challenge title and questions are stored on the server.
- Optional Google sign-in: if you sign in, we store your email and name as provided by Google, and a copy of your progress so you can restore it on another device. Your first name, weekly points and class code (if you enter one) are visible to other signed-in students in the weekly ranking. We do not send you messages or share your email.
- Questions to the teacher: if you send a question with the "Ask" button, its text and the lesson or question it is about are stored on the server with your account and read by the app owner, who answers in the notes or in a video. The owner can also see the list of signed-in accounts (name, email, progress) in order to run the app.
- Other features: "Report a mistake" only adds to a counter on that question, without your name or account. The parent report and "challenge a friend" are links that carry your name and numbers; they go only to whoever you send them to and are not stored on the server.
- Children: the app is made for secondary-school students. If you are under 13, use it without signing in.
- Who stores the data: server data is hosted by Supabase, sign-in is handled by Google, and the site is hosted by Vercel. Video and WhatsApp links open outside services (such as YouTube and WhatsApp) with their own privacy policies. The app has no ads and no tracking tools. Daily reminders in the mobile app are local notifications.
- Deletion: you can erase the progress on your device from "Me", then "Reset my progress". To delete your account, a result or a challenge from the server, write to .