Who we are
Lerno is operated by LiJie Xu, an individual (sole trader) based in China, who is the controller of your personal data. Contact: greyapps@icloud.com.
What we collect
Account details (name, email, age band), study content you upload, learning activity (answers, streaks, XP) and basic device information. Payments are processed by Paddle; we never see your card number.
How we use it
To provide and improve the service, personalise your study schedule, keep your account secure and send the notifications you choose. We rely on our contract with you to run the service, on legitimate interests for security and product improvement, and on your consent for optional analytics and marketing emails.
AI processing
Study material is sent to our AI gateway provider (AiHubMix) and its model providers only to generate your cards, explanations and tests. We do not send your name or email with it.
Sub-processors and transfers
Google Firebase (data and sign-in), Vercel (hosting), Paddle (payments and tax), AiHubMix (AI) and our email provider. Some of them process data outside your country; we only use providers that protect it with appropriate safeguards such as standard contractual clauses.
How long we keep it
Account data is kept while your account is open and deleted within 30 days after you delete the account. Uploaded source files are deleted 30 days after import. Payment records are kept by Paddle as required by tax law.
Your rights
You can access, export or delete your data at any time from Settings, or by emailing greyapps@icloud.com. You can also object to processing, ask us to correct data, or complain to your local data protection authority.
Children
You must be 13 or older to use the service. Accounts for 13-17 year olds get high-privacy defaults.
Changes
We will post updates here and tell you about important changes by email or in the app.
Questions? Email greyapps@icloud.com.