Privacy Policy

knojo is a spaced-repetition learning app for iOS, Android, and the web. The data controller responsible for your personal data is:

This policy covers the knojo mobile apps, the knojo website at knojo.app, and the backend services that power them (together, the “Service”).

We only collect data that's needed to provide and improve the Service. Here is everything we process and why.

We do not collect precise location, contacts, photos, health data, or biometric data.

• Provide the Service — create and secure your account, store your cards and goals, and run your spaced- repetition review schedule.
• Generate learning content — turn text you submit into flashcards and quizzes using AI (see §5).
• Send reminders — deliver the daily review notification you opt into.
• Process subscriptions — unlock and manage knojo Pro.
• Improve knojo — analyse aggregated usage to fix bugs and prioritise features.
• Security & compliance — detect abuse, prevent fraud, and meet our legal obligations.

We do not use your personal data for third-party advertising, and we do not sell it.

If you are in the European Economic Area or the UK, we rely on the following legal bases under Article 6 GDPR:

• Performance of a contract — to create your account and provide the core learning features you sign up for.
• Legitimate interests — to secure the Service, prevent abuse, and improve knojo through aggregated analytics, in a way that does not override your rights.
• Consent — for optional push notifications; you can withdraw it at any time in your device settings.
• Legal obligation — where we must retain records (for example, for tax or accounting of purchases).

When you choose to generate flashcards or a quiz from your notes, the relevant text is sent to our AI provider, OpenAI, which processes it to return the generated cards or questions. Only the content you explicitly submit for generation is sent — not your whole account.

OpenAI processes this data as our service provider under its API data-processing terms, and does not use data submitted through its API to train its models. We do not use AI to make any decision that produces legal or similarly significant effects about you.

We never sell your data. We share it only with the service providers (“sub-processors”) that help us run knojo, each bound to protect it and use it only on our instructions:

We may also disclose data if required by law, to enforce our terms, or to protect the rights and safety of our users — and, if knojo is ever involved in a merger or acquisition, as part of that transaction (you will be notified).

We aim to store personal data in the EU. Some of our providers (for example, OpenAI and Amplitude) may process data in the United States. Where data leaves the EEA, we rely on appropriate safeguards such as the European Commission's Standard Contractual Clauses to ensure your data remains protected.

We keep your personal data for as long as your account is active. When you delete your account, your account and learning content are permanently deleted from our production database, typically within 30 days, except where we must retain limited records to meet legal obligations (such as purchase records for tax purposes). Aggregated analytics that can no longer identify you may be retained.

We use industry-standard measures to protect your data, including encryption in transit (HTTPS/TLS), passwordless sign-in (so there is no password for us to store or leak), access controls, and reputable infrastructure providers. No method of transmission or storage is completely secure, but we work to protect your data and will notify you and the relevant authority of a breach where required by law.

If you are in the EEA or the UK, you have the right to:

• Access a copy of the personal data we hold about you.
• Rectify inaccurate or incomplete data.
• Erase your data (“right to be forgotten”).
• Port your data to another service.
• Restrict or object to certain processing.
• Withdraw consent at any time, without affecting processing already carried out.

To exercise any of these rights, email privacy@knojo.app. You also have the right to lodge a complaint with your local data protection authority — in the Netherlands, the Autoriteit Persoonsgegevens.

If you are a California resident, the CCPA/CPRA gives you the right to:

• Know what personal information we collect and how we use and share it (described in this policy).
• Access and delete your personal information.
• Correct inaccurate personal information.
• Opt out of the “sale” or “sharing” of personal information. We do not sell or share your personal information as those terms are defined under California law.
• Not receive discriminatory treatment for exercising your rights.

To make a request, email privacy@knojo.app. We will not discriminate against you for exercising these rights.

You are always in control of your data. You can permanently delete your account and all associated learning content:

• In the app — open Settings, choose Delete account, and confirm.
• By email — write to privacy@knojo.app from your account email and we will delete your account for you.

Deleting your account removes your profile, cards, goals, source text, quizzes, and review history from our production database (see §8 on retention).

If you opt in, knojo sends a single daily reminder to review the cards that are due. To do this we store a push token for your device. You can turn notifications off at any time in your device settings; doing so stops all reminders.

The knojo website uses only the cookies necessary to run the site and keep you signed in (for example, authentication and session cookies). We do not use advertising or cross-site tracking cookies on the website.

knojo is a general-audience app and is not directed to children under 13 (or under 16 in the EEA). We do not knowingly collect personal data from children under those ages. If you believe a child has provided us with personal data, contact us at privacy@knojo.app and we will delete it.

We may update this policy from time to time. When we make material changes, we will update the “Last updated” date above and, where appropriate, notify you in the app or by email. Your continued use of knojo after an update means you accept the revised policy.

Questions about this policy or your data? Reach us any time: