Privacy policy

Last updated: 2026-07-15

Lexido is a language-learning flashcard app for iOS. We try to keep this short and concrete, what the app sends off your device, what we keep, and what we don’t.

The one identifier we have

The first time you open Lexido, the app generates a random identifier and stores it in your device’s keychain. It is not your name, your email, or your Apple ID, and it is not supplied by Apple. It is a random value that means nothing outside Lexido.

That identifier is sent with every request the app makes to our backend. We use it for exactly two things:

• To know whether your Lexido Pro subscription is active.
• To count how much AI generation you have used in the current billing period, so we can apply your plan’s fair-use limit.

We do not use it for advertising, we do not use it to track you across other apps or websites, and we do not sell or share it. If you delete your account from within the app, that identifier is discarded and the next request uses a fresh one.

Use of AI

Lexido uses artificial intelligence to generate flashcard content. Specifically:

• Example sentences, glosses, and word selection are produced by large language models (Mistral, DeepSeek, OpenAI, Anthropic, or Google models routed via OpenRouter).
• Card images are produced by Cloudflare Workers AI (FLUX) and, occasionally, Google Gemini image generation.
• Native-voice audio is produced by Microsoft Azure Speech.

When these AI services are called, they receive only the language code and the word you’re studying (or, for Lyric Vocab, the lyrics of the song you provided). Your identifier is never passed on to them. It stops at our backend.

What stays on your device

• Your decks. Anything you import from a .apkg file lives only in the app’s local database. It never leaves your phone.
• Your review progress. Card ratings, scheduling state, and daily counts are stored locally and are not uploaded.
• App settings (active language, sound options, notification preferences, and so on).

If you uninstall the app, all of this is gone with it.

Imported content (.apkg files)

If you import an Anki .apkg file:

• The contents are unpacked and stored only in the app’s local database on your device.
• Lexido does not upload the imported deck, its media, or its review history to our backend.
• We do not inspect, index, or store the files you import.

You are responsible for ensuring you have the right to use any deck you import. Most Anki community decks are free to use; some are licensed for personal, non-commercial use only.

What leaves your device

Lexido contacts our backend (hosted on Cloudflare Workers) only when you actively use a feature. Every one of these requests carries the identifier described above.

• Browsing the curated catalog, fetches deck metadata and card content from a shared library.
• Lyric Vocab, when you type a song name, the artist and title are sent to lrclib.net (a community lyrics database) through our backend to fetch the lyrics. lrclib does not receive your identifier.
• Generate cards from a theme or paste, the language, your prompt, and the resulting word list are sent to our backend, which calls the AI services listed above.
• Word lookup and tokenization, the sentence or lyric text is sent to our backend for analysis.

For each of these requests, our backend may keep:

• Generated content (cards, images, audio) in a shared cache, so the same word is instant and free for the next person who studies it. This cache is keyed on the language and the word itself. It is not linked to you, and your identifier is not stored alongside it.
• Operational logs (which route was called, how long it took, how many cards were generated, and the prompt text for AI requests). These are used to spot bugs and outages. They do not contain your identifier or your IP address. To stop one device from overloading the AI features, we count requests against a one-way scrambled tag derived from your IP. We can’t turn that tag back into your address, and we don’t store the address itself.

Usage analytics and diagnostics

Lexido collects a small amount of first-party usage and diagnostic data, sent to our own backend. We do not use a third-party analytics SDK, and none of this is used to track you across other apps or websites.

• Usage analytics. Which screens you reach and which features you start and finish, so we can see where the app confuses people. These events carry a separate random identifier, generated on first launch and stored on the device. It is deliberately not the identifier used for your subscription, and the two are never joined, so your usage data is not linked to your subscription or to you.
• Diagnostics. When something errors, we send the error, the screen it happened on, and the recent in-app steps that led to it. This is used to fix crashes and bugs.

You can clear both by deleting the app, which removes the stored identifiers.

Subscriptions

If you subscribe to Lexido Pro, the App Store handles the purchase. Apple sends us:

• The Apple-supplied transaction identifier for your subscription.
• The product you purchased (monthly or yearly) and its current status.

We store this against your random identifier so the app knows whether your Pro features are active. We never see your Apple ID, email, name, or payment details. That stays between you and Apple. Cancellation and refunds go through Apple, in Settings → Apple ID → Subscriptions.

We also keep a per-subscription count of how much AI generation you have used in the current billing period, so we can apply your plan’s fair-use limit. Nothing about your subscription is sold or shared.

What we don’t collect

• No account, no sign-in, no email address, no name, no password.
• No advertising identifiers (IDFA), and no tracking across other apps or websites.
• No third-party analytics SDKs. (We do collect first-party usage and diagnostic data, described above.)
• No location data.
• No contacts, photos, microphone, or camera access.
• No upload of your review history or your imported decks.

App Store privacy label

In App Store Connect, Lexido declares the data described on this page. The identifier above and your subscription status are the only things tied to you. We do not use any of it for tracking as Apple defines it, and we do not share it with data brokers or advertisers.

If that ever changes, the label, this page, and the in-app disclosure all change at the same time, before the feature turns on.

Third parties

• Cloudflare, runs our backend and stores generated content. Cloudflare’s privacy policy.
• Apple, handles subscriptions and payment. We receive only a transaction identifier and its status.
• OpenRouter, routes language-model requests to upstream providers. OpenRouter’s privacy policy.
• Mistral AI / DeepSeek / OpenAI / Anthropic / Google, the underlying language and image models used via OpenRouter.
• Microsoft Azure Speech, synthesizes the audio for cards.
• lrclib.net, community lyrics database queried for Lyric Vocab.

We send these services only the minimum needed to fulfil your request. None of them receive the identifier we hold for you.

Your choices and your rights

• Delete everything we hold. Deleting your account from within the app erases your progress and review records and discards your identifier, which is the only key linking your subscription record to your device. Uninstalling the app removes everything stored locally, including the separate analytics identifier. Usage and diagnostic events already sent are not tied to your subscription identity and cannot be looked up per person, so they are cleared on our retention schedule rather than on request. If you want them removed sooner, email us and we will do it.
• Ask us anything. If you want to know what we hold, or want it erased, email support@getlexido.com and we will do it.

Depending on where you live, you may have additional rights over your personal data, including access, correction, erasure, and portability. The address above is how to use them, and we will not charge you or make it difficult.

Children

Lexido is not directed at children under 13, and we do not knowingly collect personal data from them. There is no account system, no advertising, no social feature, and no user-to-user contact. If you believe a child has provided us with personal data, email support@getlexido.com and we will delete it.

Changes

If we add features that change what leaves your device (for example accounts, cross-device sync, or anything social), we will update this page and show you the change in the app before the feature turns on. We will not quietly widen what we collect.

Contact

Questions about this policy? Email support@getlexido.com.

Lexido is operated by Heltra LLC.