Privacy Policy

Last updated: 31 August 2026

This policy explains what information Lunomi processes, why, and which service providers are involved. It is written in plain English rather than in legal language.

What Lunomi is

Lunomi is a multilingual vocabulary-learning mobile application. It teaches words through picture flashcards, practice exercises and short games. Lunomi is developed and published independently.

Using Lunomi without an account

Significant parts of Lunomi — studying the built-in sets, making your own decks, and the practice games — work without signing in and without an account. In that case no Lunomi account exists and no profile is created for you. Product analytics, described below, still applies.

Lunomi accounts

A Lunomi account is a username and a password that you choose in the app. There is no Google Sign-In, and we do not ask for an email address or a phone number in order to create one.

• Your password is handled by Supabase, our authentication and backend provider, which stores it only in hashed form. Lunomi never sees or stores your password, and nobody working on Lunomi can read it or look it up.
• For technical reasons, the authentication system Lunomi uses identifies accounts by an address-shaped value. Lunomi generates one internally from your username. It is not an email address, it cannot receive mail, it is never shown to you or to anyone else, and it is not contact information. We do not use it to contact you, because it cannot be used to contact anyone.
• Because there is no email address on your account, there is no “reset by email” option. Instead, when you create an account you are shown a one-time recovery code. Only a hashed form of that code is stored, so we cannot retrieve or tell you your code later.
• If you lose both your password and your recovery code, your account cannot be recovered. We are not able to verify who you are by any other means, and we will not do so.

Account, profile and online features

An account is what enables the online parts of Lunomi. Where you use those features, data of the following kinds may be stored on our behalf by Supabase:

• your Supabase authentication account, which holds your hashed password and the internal identifier described above;
• a hashed form of your recovery code;
• the public Lunomi username and profile you choose — this is chosen by you inside the app and is visible to other Lunomi users, who can find you by it and add you as a friend;
• friendships and friend requests between Lunomi accounts;
• results you submit to the daily Compete challenge;
• streak information;
• podium and achievement counts, and related online progress data.

If you never sign in, none of the above exists for you.

Data stored on your device

Lunomi also keeps learning and application data locally on your device, so that the app works offline. This includes things such as your language settings, the decks and cards you create, and your progress in the games.

This local data stays on the device. It is removed when you clear the app's data or uninstall Lunomi. Deleting your Lunomi account does not, by itself, erase data that is stored only on your device.

Product analytics

Lunomi collects a small amount of product analytics so that we can understand how the app is actually used and decide what to improve.

Lunomi does not include the Amplitude mobile SDK. Analytics events are sent from the app to a Lunomi-controlled Supabase Edge Function, which checks each event against a fixed list of permitted event names and properties and then forwards it to Amplitude's HTTP API. Anything that is not on that list is not forwarded.

Analytics is used to understand things such as:

• app and session usage;
• whether people complete onboarding;
• use of the Work, Play and Compete sections;
• which games are started and completed;
• how often people reach the daily Play limit and ask for more;
• retention and aggregate product usage over time.

Identifiers used for analytics

Analytics uses a single identifier: a random installation identifier that the app generates for itself and stores on your device. It is used to group events that came from the same installation of the app.

• It is not derived from your Lunomi account, your username, or any device, hardware or advertising identifier.
• Signing in does not change it and does not add another one. The same random identifier is used whether you are signed in or not, so analytics is not tied to your Lunomi account.
• Reinstalling Lunomi, or clearing the app's data, can produce a new one.

This means analytics measures a single installation rather than a person. We do not attempt to link analytics across your devices, and we do not send your account identifier — or any value derived from it — to our analytics provider.

What analytics is designed not to send

Analytics events are built from a fixed list of permitted properties, which is designed so that the following are not included:

• your password, your recovery code, or the internal identifier described above;
• your Lunomi username, or your real name;
• your Lunomi or Supabase account identifier, or any value derived from it;
• the text of custom decks or cards you create;
• the usernames or identities of your friends;
• precise location;
• an advertising ID;
• Android hardware identifiers.

IP-based geolocation is intentionally disabled in the analytics forwarding configuration, so location information is not derived from the network request that carries these events.

This section describes how the app is designed and configured. It is a description of our current implementation, not a guarantee about the internal behaviour of third-party systems.

Why we process this data

• To sign you in and keep you signed in. Authentication data exists so that your account can be identified across sessions and devices.
• To provide the online features. Profiles, friends, Compete results, streaks and achievement counts exist so that those features work at all.
• To operate and secure the service. Basic technical processing by our providers is required for the app to communicate with our backend.
• To understand and improve the product. The analytics described above.

We do not sell personal data, and we do not use Lunomi data for advertising or advertising personalisation.

Service providers

• Google — the operator of the Google Play distribution platform. Lunomi no longer uses Google Sign-In.
• Supabase — our authentication and backend service provider. It stores the account, profile and online-feature data described above, and hosts the Edge Function that forwards analytics.
• Amplitude — our product analytics service provider. It receives the analytics events described above, after they have been filtered by our own server.

These providers operate infrastructure that may be located in countries other than your own. Each has its own privacy documentation, published on its own website.

Retention, and deleting your account

Account-related data is kept for as long as your Lunomi account exists.

You can delete your Lunomi account from inside the app, or by emailing us. Deleting the account is intended to delete the account and its associated server-side Lunomi data, including applicable profile, social and Compete data. Data stored only on your device may remain there until you clear the app's data or uninstall Lunomi.

Full instructions are on the Delete Account page.

Analytics is not tied to your Lunomi account. Analytics events carry only the random installation identifier described above, and no account identifier or identifier derived from one, so there is no link between them and the account being deleted. They are aggregate product-usage records, they are not part of the account record, and they are not retrievable by reference to an account.

Children and families

Lunomi is intended to be suitable for children and families, and this shapes what it does:

• there is no advertising and no advertising SDK in the app;
• no advertising ID or hardware identifier is collected;
• there are no in-app purchases and no subscriptions;
• the main learning features work without an account at all;
• creating an account needs no email address, no phone number and no account with any other company;
• the public profile name is chosen inside the app and is not taken from any other account, so a child's real name is not put on a leaderboard;
• analytics is limited to the aggregate product measurements described above.

This section describes how Lunomi is built. It is not a statement of certification or approval under any particular children's privacy law or programme.

If you are a parent or guardian and you have a question about a child's use of Lunomi, or you would like an account removed, please email lunomi.app@gmail.com.

Changes to this policy

This policy may be updated as Lunomi changes. When it is, the “Last updated” date at the top of this page will change. Significant changes will be reflected here before or at the time they take effect in the app.

Contact

For any question about this policy, or about the data held for your account, email lunomi.app@gmail.com.