Privacy Policy

1. Introduction

Kata is provided by Techsign Solutions GmbH, Aeschengraben 29, 4051 Basel, Switzerland ("we", "us", or "our"), which is responsible for the processing of your personal data. We operate the Kata mobile application, website, web app and Chrome extension (collectively, the "Service"). This Privacy Policy explains how we collect, use, and protect your personal information when you use our Service. It follows the Swiss Federal Act on Data Protection (FADP) and, for users in the European Union and the European Economic Area, the General Data Protection Regulation (GDPR).

2. Information We Collect

Account Information

When you create an account, we collect your email address, your first name if you give it, and your password, which we store only in hashed form.

Learning Data

We store vocabulary items you add, study session records, grammar lesson progress, drill mastery data, spaced repetition schedules, streak information, and language preferences. This data is essential to providing the Service.

Usage & Analytics Data

We collect usage analytics in the iOS app and the web app (such as screens viewed, features used, session length, app version and device type) to improve the Service. The apps also send crash and error reports so we can find and fix problems. This data is processed by PostHog on servers in the EU and linked to a pseudonymous account ID, never to your name or email address. To see in which countries and cities Kata is used, PostHog derives an approximate location (country, region and city) from your IP address when the data arrives and then discards the IP address; it is not stored. In the web app (not in the iOS app), we also record sessions, meaning how you move through the pages, to find the places where the app is hard to use; everything you type and your account email address are masked in these recordings, and recordings are deleted after 30 days. On this website, PostHog counts visits without cookies and without storing anything on your device; these visits stay anonymous and are not linked to any account. If you come to the web app through one of our ads or another tagged link, the web app records which campaign and ad the link belongs to, so we can tell which campaigns bring people to Kata. We do not use any of this data for advertising and do not track you across other apps or websites. You can switch usage statistics off in the app's Settings on iOS and on the web (this also stops session recordings), or object at any time by emailing support@kata-languages.com.

Purchase Information

If you subscribe to Kata Pro, you buy it from Apple (App Store) or from Paddle (web app). As the sellers, they process your payment and billing data (such as your name, email address, country, payment method and orders) as independent controllers under their own privacy policies (Paddle: https://www.paddle.com/legal/privacy). We never receive your payment card details. Our subscription provider RevenueCat manages your subscriptions: it receives your pseudonymous account ID, the email address of your account (so that our support can find your subscription) and your subscription and purchase status (product, price, store, dates and renewal), and in the iOS app also the identifier for vendors (IDFV) that Apple gives every app developer. We receive the subscription status and expiration date from RevenueCat to unlock Pro. When you cancel or withdraw with us, or delete your account, we give Paddle the identifier of your web subscription so that it can be cancelled or refunded.

Cancellations and Withdrawals

When you use "Cancel contracts here" or "Withdraw from contract here", we process what you enter (your email address, your name if you give it and, for a cancellation, its type, reason and requested end date) together with the time we received it, to carry out your declaration (for a subscription from the web app, with Paddle), confirm it to you by email and, where needed, pass it on to our support. To prevent abuse of these public pages, we count requests per IP address and per email address in a non-reversible (hashed) form.

Support Requests

When you send us a support request, we receive your message, your account email address (so we can reply), any screenshots you attach, and technical details about the app and your device (app version, device model, operating system version, language settings and recent error messages). This information is stored in our support ticket system and used only to handle your request.

Emails About Technical Changes

With a Kata account, you receive emails about technical changes to Kata, for example about changes to features, about maintenance, or about changes that affect your account or how you use Kata. They are switched on automatically when you create an account; this also applies to existing accounts. You can unsubscribe at any time, in the app under Settings → Account (on iOS and on the web) or with the unsubscribe link in each of these emails, and switch them back on the same way. If you unsubscribe, you will still receive emails about your account or subscription (for example, to reset your password). To send these emails, we process your email address, your app language, whether you receive them or have unsubscribed, when you last changed this setting, and which of these emails we have sent you. They are sent through Resend. The record of sent emails is deleted with your account.

News, Offers and Learning Reminders by Email

We send you news, offers and learning reminders by email only if you have consented: by ticking the box provided for this when you sign up (it is not pre-ticked) or by turning on the switch in the app under Settings → Account (on iOS and on the web). Consent given at sign-up only takes effect once you have confirmed your email address; the confirmation email points this out. We have not subscribed existing accounts to these emails. These emails contain news about Kata and new features, offers (for example about Kata Pro), a reminder if you have not studied for 7 days and another after 30 days, and one email about Kata Pro 14 days after your Kata Pro subscription or a free Pro period ends. So that the reminders and the Kata Pro email arrive at the right time, we use the date of your last learning activity (from your learning data) and the date your Kata Pro ended; we use no other data for this purpose. The 7-day reminder may also say how many of your cards are due for review. Beyond that, we do not analyze your data for these emails or build a profile of you. The emails contain no tracking pixels, so we do not record whether you open them; links in them may carry campaign details, as described under "Usage & Analytics Data". To send these emails, we process your email address, your app language, whether you have consented, and which of these emails we have sent you. We record every consent and every withdrawal with its time, where it happened (for example at sign-up, in Settings or through the unsubscribe link) and the version of the consent text, so that we can prove your consent. You can withdraw your consent at any time with effect for the future: with the switch in Settings, with the unsubscribe button in any of these emails, or by emailing support@kata-languages.com. Withdrawing your consent only affects these emails; it does not affect the emails about technical changes or the emails about your account or subscription. These emails are sent through Resend. The record of your consents and of the emails sent is deleted with your account.

3. How We Use Your Information

• To provide and maintain the Service
• To sync your learning data across devices via our cloud backend
• To manage your subscription and premium features
• To improve and optimize the Service through analytics
• To communicate with you about your account or the Service (e.g., password resets, critical updates)

Legal bases: we process your account, learning, purchase and support data because we need it to provide the Service you signed up for (performance of a contract, Art. 6(1)(b) GDPR). Usage statistics, crash and error reports, the approximate location and, in the web app, session recordings are based on our legitimate interest in keeping the Service stable and improving it (Art. 6(1)(f) GDPR); you can object at any time by switching usage statistics off in the app's Settings or by emailing us. Emails about technical changes inform you about the Service you use; we send them to perform our contract with you (Art. 6(1)(b) GDPR) and based on our legitimate interest in informing you about changes (Art. 6(1)(f) GDPR); you can object at any time by unsubscribing. We send you news, offers and learning reminders by email only with your consent (Art. 6(1)(a) GDPR); this consent is also the basis for our use of the date of your last learning activity and the date your Kata Pro ended for these emails. You can withdraw your consent at any time with effect for the future; we keep a record of consents and withdrawals because we must be able to prove consent (Art. 7(1) GDPR). We keep purchase and billing records where accounting and tax law require it (Art. 6(1)(c) GDPR). We process cancellations and withdrawals and keep a record of them because the law requires it (Art. 6(1)(c) GDPR, for example §§ 312k and 356a of the German Civil Code).

4. Third-Party Services

We use the following third-party services:

• Supabase — Cloud database, authentication, and data storage
• RevenueCat — Subscription and in-app purchase management; receives your account ID, your email address and your subscription and purchase status (in the iOS app also the identifier for vendors)
• PostHog (EU) — Product analytics, crash and error reports, and session recordings in the web app
• Apple App Store / Paddle — Sale of Kata Pro and payment processing (as sellers, independent controllers)
• Resend — Sending our emails (for example about your account or subscription, about technical changes to Kata and, if you have consented, news, offers and learning reminders)
• Google Cloud (Gemini API, Text-to-Speech) — Translations of the words you look up in the Chrome extension (and of subtitle lines if OpenAI is unavailable) and natural pronunciation audio. Only the text to be translated or read aloud is sent.
• OpenAI — Translation of subtitle lines in the Chrome extension. Only the text to be translated is sent.

Each third-party service operates under its own privacy policy. We only share the minimum data necessary for each service to function. Every provider that processes personal data on our behalf is bound by a data processing agreement that obliges it to protect your data at least as well as this policy describes.

Supabase and PostHog store your data on servers in the European Union (Frankfurt, Germany). RevenueCat, Google, OpenAI and Resend may also process data in the United States. Where data goes to a country without an adequate level of data protection, the transfer is based on the EU-U.S. and Swiss-U.S. Data Privacy Framework if the provider is certified, or on the European Commission's standard contractual clauses, which the Swiss Federal Data Protection and Information Commissioner (FDPIC) also recognises. Apple and Paddle are themselves responsible for any transfers of your payment data, as described in their privacy policies.

5. Chrome Extension

The Kata extension for Google Chrome is part of Kata Pro. It only works on the websites of Netflix, YouTube, Prime Video, Disney+ and Apple TV+. It does not access other websites, your browsing history or anything you type. When you use it, it processes the following data:

• Words you look up: when you point at a word, the word and the subtitle line it appears in are sent to our server and translated.
• Dual subtitles: each subtitle line of the video you are watching is sent to our server and translated into your language. The next few lines are sent shortly before they appear, so that their translation is ready in time.
• Words you save: the word, its translation and example sentences are added to your vocabulary together with the address of the video page, the platform and the title of the video, so you can see where you found the word.
• In your browser: your sign-in session, your settings, your Pro status, recent translations (for up to 30 days) and a random identifier for usage statistics are stored locally by Chrome. Signing out removes your session and the stored translations and replaces the identifier with a new one.

The extension sends usage events to PostHog on servers in the EU, for example that a word was translated or saved and on which streaming site, linked to your pseudonymous account ID. These events never contain the words themselves, subtitles, video titles or page addresses, and no location is derived from them. The extension contains no advertising code and does not track you across other websites. These usage events cannot be switched off in the extension; you can object to them at any time by emailing support@kata-languages.com. Subtitle lines are translated with the OpenAI API (or with Google's Gemini API if OpenAI is unavailable), and the words you look up with Google's Gemini API. Only the text to be translated and the languages involved are sent to these providers, never your name or email address. Translations may be kept in a cache on our server so the same word or line does not have to be translated again.

6. Data Storage & Security

Your data is stored securely on Supabase servers. We use industry-standard encryption for data in transit (TLS) and at rest. Authentication tokens are stored securely in your device's keychain. We do not sell, rent, or share your personal data with third parties for marketing purposes.

7. Data Retention

We retain your data for as long as your account is active. If you delete your account, we will delete your personal data within 30 days, except where we are required by law to retain it. Analytics data linked to your account is deleted when you delete your account.

8. Your Rights

You have the right to:

• Access the personal data we hold about you
• Request correction of inaccurate data
• Ask us to restrict the processing of your data
• Request deletion of your account and data
• Export your learning data
• Object to usage analytics at any time, by switching usage statistics off in the app's Settings (on iOS and on the web) or by emailing us
• Object to emails about technical changes at any time, by unsubscribing in the app's Settings (on iOS and on the web) or with the link in any of these emails
• Withdraw your consent to news, offers and learning reminders by email at any time with effect for the future, by turning off the switch in the app's Settings (on iOS and on the web), using the unsubscribe button in any of these emails or emailing us

To exercise any of these rights, contact us at support@kata-languages.com.

You also have the right to lodge a complaint with a data protection authority: in Switzerland with the Federal Data Protection and Information Commissioner (FDPIC), in the EU/EEA with the authority in the country where you live or work.

9. Children's Privacy

Our Service is not directed to children under 13. We do not knowingly collect personal information from children under 13. If you believe we have collected data from a child under 13, please contact us and we will promptly delete it.

10. Changes to This Policy

We may update this Privacy Policy from time to time. We will notify you of significant changes by posting the new policy on this page and updating the "Last updated" date. Your continued use of the Service after changes constitutes acceptance of the updated policy.

11. Contact Us

If you have questions about this Privacy Policy, please contact us at support@kata-languages.com or by post at Techsign Solutions GmbH, Aeschengraben 29, 4051 Basel, Switzerland.