Privacy Policy

Below is the complete list. Nothing else is collected.

Account data

• ·Display name — chosen by you, or taken from your Google account when you sign in with Google.
• ·Email address — from the sign-up form or your Google account.

Authentication is handled by Firebase Authentication. We never see or store your password; email/password accounts are verified by Firebase, and Google Sign-In never shares your password with us at all.

Learning data

Stored in Firebase Firestore, tied to your account:

• ·Per-word study state for every word you have seen: memory stability and difficulty, review interval, next review date, last studied date, lapse count, and learning status.
• ·Streak count, XP, level, lumens balance, total words learned, and your current CEFR deck (A1–C2).
• ·A per-day history of XP earned and words studied, used to draw your stats charts and activity heatmap.
• ·Your placement-test result.
• ·Achievements unlocked and cosmetic items owned or equipped.

Social data

Only created if you use the social features:

• ·Your friend code — an eight-character code, generated for you, that other users can search for.
• ·Your friends list, and friend requests you have sent or received.
• ·Nudges you send to friends or receive from them.
• ·Duel records: the opponent, both scores, and your display name stored alongside them.
• ·League membership and weekly standings, and weekly contest results.
• ·Daily challenge scores.

Settings

• ·Your language pair (the language you know and the one you are learning) is stored both on your device and on your account, so it follows you to a new device.
• ·Notification preferences, session settings, theme, quest progress and onboarding status are stored only on your device and are never uploaded.

Analytics and diagnostics

The app sends Firebase Analytics events so we can see which parts are used and where people get stuck: session started, session completed, exercise shown, exercise answered (correct or not), game played and score, onboarding step reached, onboarding completed. Your chosen language pair is set as an analytics property. These events are not tied to your name or email in any report we look at.

In release builds only, Firebase Crashlytics reports crashes, including a stack trace and basic device information (model, OS version). Debug builds report nothing.

What we never collect

No payment information (there is nothing to buy), no precise or approximate location, no contacts, no camera access, no microphone access, no biometrics, no advertising identifiers, and no third-party advertising or tracking SDKs of any kind.

The app requests only these Android permissions: internet access, notifications, vibration, alarm scheduling (for reminders), and start-on-boot (so scheduled reminders survive a restart).

This is the part most policies leave out, so we are being specific.

Lumina’s social features need users to be able to find and see each other. As a result, the following fields on your profile are readable by any signed-in Lumina user, not only your friends:

• ·your display name, level, XP, streak, lumens balance, and friend code;
• ·your email address — a technical consequence of how the profile record is stored, not something the app displays anywhere to other people;
• ·your daily challenge scores.

In addition:

• ·Friends can see your streak, total words learned, weekly XP chart, and the date you became friends.
• ·League opponents (up to 19 other people per weekly bucket) see your display name and weekly XP.
• ·Duel opponents see your display name and score.

• ·To run the app: scheduling your reviews, tracking progress, awarding XP and lumens, and syncing across devices.
• ·To send the daily-word and streak reminders you have enabled. These are scheduled and delivered on your own device — no reminder content is sent from a server.
• ·To operate the social features you choose to use.
• ·To fix crashes and understand which features are actually used.

We do not sell, rent, or trade your data. We do not use it for advertising. We do not build profiles about you for any purpose outside the app.

Google Firebase (Google LLC) provides authentication, the database, analytics, and crash reporting. Your data is stored on Google’s servers and is subject to Google’s Privacy Policy. Firebase is the only third party that receives your data.

Text-to-speech is performed by whatever speech engine is installed on your phone (usually Google’s). When you tap the speaker button, the word being studied is passed to that engine. Depending on your device settings, some speech engines process text in the cloud. This is governed by your device’s and that engine’s own settings and policies, not by us.

Your data is kept for as long as your account exists.

You can delete your account at any time from Settings → Delete Account. You will be asked to type DELETE and then to confirm your identity (your password, or a fresh Google sign-in). The app then removes:

• ·all of your word study data and study history;
• ·your streak, XP, level, lumens, achievements and cosmetics;
• ·your friends list, including the copy of it held by each of your friends;
• ·all friend requests you sent or received, and all nudges;
• ·your league membership, league history, contest history and daily-challenge scores;
• ·your profile record;
• ·your login credentials; and
• ·everything the app stored on your device.

One deliberate exception: duels you played are also part of your opponent’s history, so the duel records themselves are kept — but your display name is stripped from them, leaving only an anonymous participant.

One further residue: a nudge you already sent sits in that friend’s inbox until they next open the app, at which point it is read and cleared automatically. Only the recipient can delete it, so it cannot be removed on your behalf.

Deletion is immediate and irreversible. There is no recovery, no grace period, and no backup we can restore from.

You can, at any time and without asking us:

• ·See your data — everything the app holds about you is visible in the app itself (Profile, Stats, Vocabulary, and the word detail pages).
• ·Correct it — change your display name, language pair and settings in Settings.
• ·Delete it — Settings → Delete Account, as described above.

If you are in a jurisdiction that grants additional rights over your personal data (such as the EU/UK GDPR), email contact@lhkspace.com and we will act on your request.

Lumina is not directed at children under 13, and we do not knowingly collect data from anyone under 13. If you believe a child has given us personal information, email us and we will delete it.

Data in transit is encrypted (HTTPS/TLS). Access to your account data is restricted by Firebase Security Rules so that only you can write it, and only the profile fields listed in section 2 are readable by other users. No system is perfectly secure, and we cannot guarantee absolute security.

We may update this policy. When we do, the effective date above changes. Continuing to use the app after an update means you accept the revised policy.