Czechify
Learn Czech with confidence
Czechify is operated by Mahesh Pathak, Příčná 1892/4, Nové Město, 110 00 Praha, Czechia (the “controller”, “we”, or “us”).
For privacy questions or requests, email [email protected]. No data protection officer has been appointed because Czechify's current processing does not require one.
Czechify automatically creates an anonymous cloud account and synchronises learning data to it. You may optionally connect Google or add an email address for account recovery and multi-device use. The optional learner profile (name, level, study goal, focus, pace, teacher and reminder preference), placement, and learning progress synchronise so a recovered account is ready on another device. AI chat history, exam results, device settings, and downloaded lesson audio stay on your device. AI tutor text and optional cloud-pronunciation audio leave the device as described below.
There are no ads, third-party analytics or crash-reporting SDKs, and no cross-app or cross-site tracking.
| Data | Purpose | Legal basis under GDPR Article 6 |
|---|---|---|
| Anonymous account ID, installation/device ID, authentication session, and basic network/security metadata such as IP address, user agent, request time and status | Create and secure the account, operate the service, prevent abuse, diagnose failures, and resolve sync conflicts | Contract, Art. 6(1)(b), for the account and service; legitimate interests, Art. 6(1)(f), for proportionate security and abuse prevention |
| Synced learning data: lesson completion and scores, XP, streaks, badges, review/SRS state, custom cards, and gamification state | Save progress and keep it consistent across installations | Contract, Art. 6(1)(b) |
| Optional learner profile and preferences: name, self-assessed level, study goal, focus skills, broad target horizon, study pace, teacher choice, reminder time/intention, and placement result | Restore the account on another device and tailor the learning plan. Goals such as residence, work, study, or family are optional. Notification permission and actual schedules remain device-specific. | Contract, Art. 6(1)(b) |
| Account-level curriculum access entitlement, when support or reviewer access has been granted | Make the authorised course content available and administer temporary access | Contract, Art. 6(1)(b) |
| Email address and password credential (only if you link an account) | Sign-in, account recovery, and multi-device use. Supabase stores the password credential; Czechify does not receive your plain-text password. | Contract, Art. 6(1)(b) |
| Google account email, provider account identifier, and basic profile fields such as name and profile image (only if you connect Google) | Sign-in, account recovery, and multi-device use. Czechify requests no access to Google Drive, contacts, or other Google account content. | Contract, Art. 6(1)(b) |
| AI tutor messages, recent conversation context, and writing submitted for evaluation | Generate the reply, correction, summary, or writing assessment you request | Contract, Art. 6(1)(b). Using AI features is optional; the rest of the course remains available without them. |
| Short pronunciation recording (only when cloud speech is enabled) | Transcribe speech so the app can compare recognised words with the prompted phrase; this is not acoustic diagnosis of individual sounds | Consent, Art. 6(1)(a). You may refuse or withdraw without losing the rest of the app. |
| Daily AI/speech usage counters and security events | Enforce fair-use limits and protect Czechify and its providers from abuse | Legitimate interests, Art. 6(1)(f) |
| AI-reply report: reported tutor output, scenario, time, reason, and any note you add; plus sender details supplied by your email app | Investigate safety or quality reports and respond where appropriate | Legitimate interests, Art. 6(1)(f), in maintaining a safe and reliable service |
| Privacy/support email and evidence that a request was completed | Answer you, fulfil legal requests, and demonstrate compliance | Legal obligation, Art. 6(1)(c), and legitimate interests, Art. 6(1)(f) |
Data is obtained from you, generated by your use of Czechify, or supplied automatically by your device and network. You do not have to provide a name or linked email. Without the automatically created account and synced identifiers, cloud sync and cloud-backed features cannot operate. Without AI text or voice audio, the specific AI or cloud-speech request cannot be performed.
Do not put health, biometric, political, religious, financial, identity-document, or other sensitive personal information into the AI tutor or support reports. Czechify does not need it.
AI conversation history, exam results, visual/device settings, notification permission and scheduled notification identifiers, device consent history, and downloaded lesson audio are stored locally. The optional learner profile, reminder preference, placement, and learning progress also have a local copy but the categories listed as synced above are sent to the cloud. Authentication tokens are stored using Android Keystore or Apple Keychain facilities. Android app backup is disabled.
Your device's default speech-recognition feature may process audio on the device or send it to the operating-system provider (for example, Google or Apple), depending on your device and its settings. That processing is controlled by the provider's terms and privacy notice, not by Czechify.
On first use, Czechify creates a random anonymous Supabase user ID. No email, password, or name is required. Synced rows are tied to that account ID and an installation ID. You may later link an Google account or an email address and password to recover the same account or use it on another device.
Deleting an account removes the old account and its synced rows. If you continue using the app, Czechify then creates a new, empty anonymous account so cloud-backed functions can keep working.
| Recipient | Data and role | Primary location |
|---|---|---|
| Supabase, Inc. | Processor for authentication, database sync, storage, Edge Functions, quotas, and infrastructure/security logs | Primary Czechify project data: Paris, France (European Union); supporting subprocessors may operate elsewhere |
| Scaleway SAS | Processor providing Generative APIs for AI tutor, grammar, summary, and writing-evaluation requests. Czechify currently uses a DeepSeek V4 Flash model hosted by Scaleway. The request body does not contain your Czechify account ID or linked email. | Paris, France (European Union) |
| OpenAI Ireland Ltd / OpenAI, L.L.C. | Processes a pronunciation clip for transcription only after cloud-speech consent. It does not receive your Czechify account ID or linked email in the request body. | EEA and United States |
| Google LLC | Identity provider for optional Google account authentication; processes the selected account email, provider identifier, and basic profile fields. No Google content scope is requested. | May be processed globally, including in the United States |
| Google LLC (Gmail) and your email provider | Carry and store privacy/support emails and AI-reply reports that you choose to send | May be processed globally, including in the United States |
Lesson audio and curriculum are also downloaded from Supabase Storage. The request identifies the requested file and includes ordinary network metadata.
Czechify's primary Supabase project data is hosted in Paris, France, within the European Union. Supabase's Data Processing Addendum incorporates the European Commission's Standard Contractual Clauses where they are required for restricted transfers or onward transfers.
OpenAI's Data Processing Addendum uses applicable adequacy decisions and Standard Contractual Clauses for restricted transfers and onward transfers. You may ask us for information about those safeguards.
AI-text inference is performed by Scaleway in Paris, France. Scaleway states that models on its Generative APIs infrastructure operate in Europe without sending prompts or outputs to the model creator or another third-party model service. This AI-text flow therefore does not itself require a transfer outside the EEA. See Scaleway's Generative APIs data-privacy information.
Cloud speech is off until you allow it. When enabled, a short recording is sent over encrypted connections through a Supabase Edge Function to OpenAI, and the transcript returns to the app. Czechify does not write the recording or transcript to its cloud database and removes its temporary local recording after the attempt.
OpenAI states that API inputs and outputs are not used to train its models by default and may be retained for abuse monitoring for up to 30 days unless a zero-data-retention configuration applies. You can switch cloud speech off at any time in Settings. Withdrawal affects future recordings and does not make earlier consent-based processing unlawful. The app keeps a local record of the consent/withdrawal time and notice version until app data is cleared.
AI output can be inaccurate, inappropriate, or offensive and is not professional advice. It does not make legal or similarly significant decisions about you. Your full chat history stays on your device, but the current message, recent context, and sometimes a generated summary are sent for each request.
Reporting a tutor reply opens your email app with the tutor output, scenario, time, reason, and optional note. Your side of the conversation is not included unless you put it in the note. Your email provider may add your name, address, signature, or other account details.
Czechify uses HTTPS/TLS, owner-scoped database row-level security, authenticated Edge Functions, server-side provider secrets, rate limits, and secure operating-system storage for authentication sessions. Access is limited to what is needed to operate and support the service. No internet service can promise absolute security; contact us if you suspect a problem.
Subject to the GDPR's conditions and exceptions, you may request access, rectification, erasure, restriction, portability, or object to processing based on legitimate interests. You may withdraw consent at any time without affecting the lawfulness of processing before withdrawal.
Export and in-app deletion are under Settings → Account & data. For an external deletion request, follow the Czechify account-deletion instructions. We may need proportionate information to verify a request. We normally respond within one month.
You may complain to the Czech supervisory authority, the Úřad pro ochranu osobních údajů, Pplk. Sochora 27, 170 00 Praha 7, [email protected], or to the competent authority where you live or work.
Czechify is not directed to children under 16 and should be listed in Google Play for an audience aged 16 and over. Czechify does not collect a birth date. A person under 16 must not enable cloud speech or submit personal data to an AI feature. If you believe a child has done so, contact us so we can take appropriate action.
We will update the date and version when this notice changes. If a change affects a consent you previously gave, Czechify will ask again before further consent-based processing.