Privacy Policy

Last updated 18 October 2026

ExplainBook helps you study your own documents with an AI tutor called Tavie. This policy explains what we collect, why, and the choices you have. We do not sell your data, show ads, or track you across other apps and websites.

What stays on your device

Your documents, photos, notebooks, drawings, typed notes, recordings and saved explanations are stored on your device (and in your own iCloud backup if you use it). We do not upload or keep copies of them on our servers.

What is sent to produce explanations

When you ask Tavie a question, present a page, solve a worksheet or create a board, the app sends the parts needed for that request (the page's text, a picture of the page or the part you circled, and your question) through our server to an AI model provider, which returns the explanation. Our server passes the request on and does not store its content. AI providers process it under their own terms and are not permitted by those terms to use it to identify you. Voice narration works the same way with the text being read aloud.

Your account

You sign in with Apple. We receive a user identifier and, if you choose to share it, an email address (which may be an Apple private relay address). We use them only to keep your credits and purchases with your account.

Purchases and credits

Purchases are handled by Apple. We receive the transaction details Apple provides (such as the product and transaction identifier) to add credits to your account. For each AI request we record the amount of credit used, the model and the time, so we can keep your balance and prevent abuse. We never receive your payment details.

Keeping and deleting data

Your account data is kept while you have an account. You can delete your account at any time in the app under Settings, Account, Delete account. This removes your account, your page balance and your usage records from our server. It does not cancel an App Store subscription; cancel that in your Apple account settings. Documents on your device are not affected.

Children

ExplainBook is a study tool and can be used by students. We do not knowingly collect more than the account and purchase information described here from anyone, and we do not use data for advertising.

Service providers

We use Supabase (account and credit storage), OpenRouter and the AI model providers it connects to (generating explanations and voices), and Apple (sign in and payments).

Contact

Problem reports

If you tap "This is wrong" or send a problem report, we receive what you chose to send: your note, the question, Tavie's answer, and pictures of the page or the part you asked about. We use them only to fix problems, and delete them on request.

Questions or requests: [contact email].