Lumika Privacy Policy

Last updated: 16 October 2026

The short version

• Lumika has no accounts and never asks who you are. Your learning progress lives on your phone.

• AI features send what they need (what you type, translate or say, and the words you're learning) to our AI providers, only after you tap Allow, and only to answer you.

• Crash reports (Android) and usage analytics are on by default, and you can switch each off.

• No ads, no advertising ID, no tracking across apps, and we never sell data.

• You can delete everything Lumika keeps on your phone in one tap.

What stays on your phone

Your word list, progress and review schedule; articles you save in the Reader; Memory Palace photos; Echo Booth recordings; the dictionary (built into the app, or downloaded once from our server the first time you open a language; looking words up never leaves your phone); words you look up with "Learn in Lumika" from another app; and anything typed with the Lumika keyboard. None of this is sent to us.

What leaves your phone, and why

AI features (only after you allow them)

The first time you use an AI feature, Lumika asks first. If you allow it:

• Ask, and translating: the text goes to Anthropic (Claude). That covers a question you type, text you select in another app with "Translate in Lumika" (Android), an article in the Reader when you tap Translate, and a word the built-in dictionary doesn't have.

• Conversation practice: your messages, the conversation so far and the words you're learning go to Anthropic.

• Daily stories and listening questions: the words you know and are learning go to Anthropic, and so does the story text for its questions.

• Memory tricks: the word and its meaning go to Anthropic.

• "One thing I noticed" (Pro): counts of the mistakes you tend to make (for example, how often you mix up two articles) go to Anthropic.

• Camera Scanner: if you tap something the phone can't name, one cropped photo goes to Anthropic. It never sends a crop in which it detects a face. If you circle a sign to translate, the text the camera reads goes to Anthropic. On Android, a sign in Russian, Ukrainian, Greek, Hebrew, Arabic or Thai, which the phone can't read itself, goes as the circled photo instead, and never one in which it detects a face.

• Precise pronunciation check (Pro+, and a few free samples): that one recording goes to Google Cloud Speech-to-Text for scoring.

Anthropic uses this only to answer you. It doesn't train its models on it, and it deletes it within 30 days (longer only if it's flagged for misuse). Google Cloud Speech-to-Text doesn't keep your recording.

We don't store your requests, with one exception. Finished translations and generated text, such as stories and memory tricks, are cached on our server, so the next learner who asks the same thing gets an instant answer. The cache is keyed by a scrambled fingerprint of the request, and it's never linked to you or your device.

Switch AI features off any time in Settings → Privacy → AI features.

Speaking practice

Pronunciation practice uses your phone's built-in speech recognition: Apple's on iPhone and iPad, Google's on Android. It may process your voice on the device or on Apple's or Google's servers, under their privacy terms. Lumika itself never receives or keeps that audio.

The voices you hear are either built into the app or generated by Google Cloud Text-to-Speech from Lumika's own words and sentences, and the generated audio is cached.

Crash reports (Android)

If Lumika crashes on Android, Firebase Crashlytics sends us:

• a technical report (the stack trace, the device model, the operating system version and the app's state at the moment of the crash);

• a random Crashlytics installation ID.

A report never includes your learning data, camera images or anything you've typed. The iPhone and iPad app sends no crash reports.

Switch crash reports off in Settings → Privacy → Share crash reports.

Usage analytics

To learn which parts of Lumika help people learn, the app sends usage events to Google Analytics for Firebase:

• which screens you open;

• which features you use: for example, a lesson finished, the subscription screen shown, a purchase or restore result, a card shared, a review requested, your answer on AI features;

• the language you're learning, your plan and your learning goal;

• the app version, device model and operating system;

• your approximate location (such as country and city), which Google Analytics works out from your IP address;

• purchases made in the app;

• a random app-instance ID.

We never send the words you learn, anything you type or read, recordings or images, and we never set a user ID. Lumika doesn't collect your advertising ID or Android ID, and it turns off Google's advertising and personalization signals.

Switch usage analytics off in Settings → Privacy → Share usage analytics.

Purchases

When you subscribe, RevenueCat, working with the Apple App Store or Google Play, records the transaction against Lumika's random install ID, so your subscription works. We never see your payment details.

The random install ID

Lumika creates a random ID on your phone. It isn't tied to your phone's hardware or to you, and it changes if you reinstall. We use it to:

• keep AI features fair to everyone: our server keeps a daily count of how often each AI feature is used per install, and enforces limits;

• recognise your subscription;

• spot abuse of the report button.

Reports you send

When you tap Report on an AI answer, we receive:

• the text of that answer;

• which feature produced it;

• the language and your platform (iPhone or Android);

• the install ID.

We use this to review the answer and improve our safeguards. We never receive your own words with a report.

What we never do

• No selling or renting of data, and no data brokers.

• No ads, and no advertising ID. We don't track you across other companies' apps or websites.

• No accounts, names, email addresses or phone numbers collected in the app.

Service providers

Each of these processes only what's described above, on our behalf and under their own privacy terms:

• Anthropic (Claude): AI answers for translation and Ask, conversation practice, stories and listening questions, memory tricks, insights, and naming objects in the Android Scanner.

• Google Cloud: Speech-to-Text for Precise checks, and Text-to-Speech for audio.

• Supabase: our server. AI requests pass through it, and it keeps the fair-use counters, the caches and reports.

• RevenueCat: subscriptions.

• Firebase (Google): Google Analytics, plus crash reporting and remote configuration on Android.

• Apple App Store and Google Play: payments and app distribution.

Your controls

• AI features: Settings → Privacy → AI features.

• Crash reports (Android): Settings → Privacy → Share crash reports.

• Usage analytics: Settings → Privacy → Share usage analytics.

• Delete everything: Settings → Delete everything immediately and permanently erases all learning data on your phone. There's no account to delete, because none exists.

• Data on our server: we can't look you up by name or email, because we never had them. Write to admin@peerware.site and we'll help remove anything tied to your install.

• Subscriptions: Settings → Manage subscription, or directly through your Apple ID or Google Play subscription settings.

Children

Lumika isn't directed at children under 13 and doesn't knowingly collect data from them.

Changes to this policy

If this policy changes, we'll update the date at the top of this page.

Contact

Questions about this policy: admin@peerware.site