Privacy policy

Who we are

Lumo is an independent learning app, published at lumostudy.app by the small team that builds it. We are the people who decide what data the app collects and why, so we are responsible for answering to you about it, and you can reach us at studywithlumo@gmail.com. This policy explains what we collect, why we collect it, who handles it for us, and what you can ask us to do with it. It covers theLumo web app and signing in to it with Google.

The short version

We collect what the app needs to sign you in, remember where you are in a chapter, and bill a subscription if you take one. We do not show advertising, we do not sell or rent your data, and we do not run analytics trackers or advertising pixels. Your data is stored with a small number of providers, all named below.

What we collect

• Account details. Your email address. If you sign in with Google, Google also sends us your name and a link to your profile picture. We store your name and email address; the picture link stays in our sign-in provider’s record for your account and is not shown anywhere in the app.
• How you found us. If you arrive through a link that carries campaign tags, for example from one of our own posts or ads, we keep those two tags — the source and the campaign name — with your account when you create it. They tell us which of our links people sign up from. They say nothing about you, and nobody outside Lumo receives them.
• Sign-in security. Single-use sign-in links sent to your email, a session cookie that keeps you signed in, and temporary counters per email address and per IP address that stop anyone from flooding an inbox with sign-in links. The counters reset after ten minutes.
• Your settings. The learning level and subjects you choose, the free books unlocked for you because of that choice, your daily goal, your notification preferences, and a display name if you add one.
• Learning activity. Which chapters you open and finish, how far you got in each, quiz results, your streak and the day you last used the app, and simple usage events such as “chapter completed”. If you search for a topic we do not have yet, we keep the search so we know what to write next.
• Payments. Stripe runs the checkout. We receive Stripe’s identifiers for your customer record and subscription, the plan, its status and its renewal date. We never see or store your card number.
• Technical logs. Our hosting provider records the IP address, browser type, requested page, time and any error for each request. We use these only to keep the app secure and working, and they are kept for a short period measured in days.

Why we use it

Under data protection law we need a reason for each use. Ours are:

• To provide the service you asked for — signing you in, remembering your progress and settings, and running your subscription.
• Our legitimate interests — keeping the app secure, preventing abuse of sign-in, fixing errors, and understanding which chapters people finish so we can write better ones. We do not use your data to build profiles of you for advertising.
• Legal obligations — keeping payment records for as long as tax and accounting law requires.
• Your consent — for anything optional, such as reminder emails if we add them. You can withdraw consent at any time in Settings.

Cookies and browser storage

Lumo uses only the cookies it needs to work: the session cookies set by our sign-in provider (their names begin with “sb-”), a cookie that remembers you have finished the welcome steps so the app opens faster, a cookie that remembers you have answered the add-to-home-screen prompt, a cookie that holds your time zone so streaks and the daily goal count days on your own clock, and, if you arrived through a link with campaign tags, a cookie that holds those tags for thirty minutes so they can be attached to a new account and is deleted as soon as it has been used. Your light or dark theme choice is stored in your browser and never sent to us. There are no advertising cookies, no analytics cookies and no third-party trackers, which is why you do not see a cookie banner.

Who processes data for us

We do not run our own servers. These companies process data on our behalf, under contracts that restrict them to our instructions:

• Supabase — sign-in, the database that holds your account and progress, and the storage that serves the app’s artwork.
• Vercel — hosting the app and keeping the technical logs described above.
• Stripe — payments and subscription billing. Stripe’s own privacy policy applies to what you enter at checkout.
• Resend — delivering sign-in emails.
• Google — only if you choose to sign in with Google, and only to confirm who you are.

We share data with nobody else, except where the law requires it or to protect the service from abuse. We never sell it.

Google user data

This section applies if you sign in with Google. It describes what Lumo receives from your Google account, what it does with it, and what it will never do with it.

• What we access. Only the data behind Google’s basic “email” and “profile” permissions: your email address, your name, a link to your profile picture, and Google’s identifier for your account. We do not request access to Gmail, Drive, Calendar, Contacts, or any other Google service, and we cannot read them.
• How we use it. To create your Lumo account the first time you sign in, and to recognise you on every sign-in after that. Your name is shown to you in the app. Nothing from Google is used for anything else.
• How we store it. Your email address and name are stored in our database and your Google account identifier in our sign-in provider’s records, both hosted by Supabase. Data is encrypted in transit and at rest, access is restricted to your own account by database rules, and the server credentials that could read other accounts never reach a browser.
• Who we share it with. Nobody, except the processors named above that host the service for us. We do not sell, rent or trade Google user data, and we do not transfer it to any third party for their own purposes.
• How long we keep it, and how to delete it. For as long as your account exists. Ask for deletion at studywithlumo@gmail.com and the account and everything tied to it is removed. You can also revoke Lumo’s access at any time from your Google account’s security settings.

We never use Google user data for advertising of any kind, never sell it to data brokers or information resellers, never use it to assess creditworthiness or for lending, never use it to train artificial intelligence or machine-learning models, and never transfer it to anyone for those purposes. Our use of information received from Google APIs follows the Google API Services User Data Policy, including its Limited Use requirements. If we ever change how we use Google user data we will tell you before the change takes effect.

Where your data is processed

Our providers may process data in the United States and other countries outside the European Economic Area. Where that happens, transfers rely on the EU–US Data Privacy Framework or the European Commission’s Standard Contractual Clauses, together with the providers’ own security measures.

How long we keep it

• Your account, settings and learning activity — for as long as your account exists. Deleting the account deletes all of it.
• Payment records — Stripe keeps invoices and transaction records for as long as tax law requires, which can be up to ten years, even after your account is gone.
• Sign-in counters — ten minutes. Technical logs — a matter of days.

Your rights

Wherever you live, and in particular under the GDPR and the UK GDPR, you can ask us to show you the data we hold about you, correct it, delete it, give you a copy in a portable format, restrict or object to how we use it, and withdraw any consent you gave. Email studywithlumo@gmail.com from the address on your account and we will answer within one month. You can also complain to the data protection authority in your country; we would rather hear from you first, but that is your choice.

Deleting your account

Account deletion is not yet a button in the app. Email studywithlumo@gmail.com from the address on your account with the subject “Delete my account”. We cancel any subscription, delete the account and everything tied to it, and confirm by reply. This cannot be undone.

Children

Lumo is not directed at children under 16, and we do not knowingly collect data from them. If you believe a child has created an account, email us and we will delete it.

Security

All traffic is encrypted in transit. The database enforces per-user access rules, so one account cannot read another’s data even if the app has a bug. Server credentials never reach the browser. No system is perfect; if you find a problem, tell us at studywithlumo@gmail.com and we will fix it quickly.

Changes to this policy

When we change this policy we update the date at the top. If a change matters — a new kind of data, a new provider, a new purpose — we tell you by email or in the app before it takes effect.