Privacy Policy

Sign in with Apple

Cinelingua uses Sign in with Apple as its sole authentication method. When you sign in, Apple provides a unique identifier and, optionally, your name and email address. You may choose to hide your email, in which case Apple provides a private relay address.

Cinelingua stores the Apple-provided user identifier and, if shared, your name and email address, in order to identify your account and associate your app data with it. This information is stored in Firebase Authentication (see below). We do not use it for advertising or share it with third parties.

Firebase Authentication

After Sign in with Apple, Cinelingua uses Firebase Authentication (Google LLC) to manage your session. Firebase receives the Apple credential, creates a session token, and returns it to the app. The app uses this token to authenticate subsequent requests to Cinelingua's backend services.

Firebase Authentication may log authentication events (sign-in, sign-out, token refresh) as part of its standard operation. Refer to Firebase's privacy documentation for details on Google's data handling.

Netflix Credentials

Cinelingua displays Netflix content through a browser view in which you sign into Netflix directly. Cinelingua does not collect, store, intercept, or have access to your Netflix username, password, or session credentials. Netflix authentication is handled entirely by Netflix's own interface and servers.

Firebase Firestore

Cinelingua uses Cloud Firestore (Google LLC) to store per-user app data, including usage quotas, feature configuration, and app settings associated with your account. This data is used to enforce subscription limits and deliver personalized app behavior.

Data is stored under your Firebase user ID and is not shared with third parties for advertising purposes. You may request deletion of your account data by contacting us at hello@jeffreychang.me.

Firebase App Check & Device Attestation

To protect backend APIs from unauthorized access, Cinelingua uses Firebase App Check with Apple's DeviceCheck attestation. This verifies that requests originate from a genuine, unmodified copy of Cinelingua on a real Apple device.

DeviceCheck communicates with Apple's servers using a device token. Apple may record that an attestation was requested from this device. No personally identifiable information is transmitted through this process. Refer to Apple's DeviceCheck documentation for details.

Translation & Vocabulary Requests

When you request a translation or vocabulary lookup, Cinelingua may send the relevant text (such as a subtitle line or selected word) to an AI translation service. This text is used solely to generate a response for your in-app query. We do not use these requests to build profiles or for advertising.

The specific AI provider(s) used may change over time. Queries are associated with your session but are not stored long-term for training purposes by Cinelingua.

Whisper On-Device Transcription

Cinelingua offers optional on-device audio transcription using the Whisper model. Once the model is downloaded to your device, all transcription processing happens locally. No audio data is sent to any server during transcription. The model download itself does not transmit any personal information.

StoreKit & Apple Payments

Cinelingua offers a Pro subscription via Apple's In-App Purchase system (StoreKit). All payment processing is handled by Apple. Cinelingua does not receive or store your payment card information.

When a subscription is active or restored, Apple provides a cryptographically signed receipt or transaction record. Cinelingua uses this to verify entitlement to Pro features. Subscription status may be synced to Firestore to enforce quotas across sessions.

To manage or cancel your subscription, go to iPad Settings → [your name] → Subscriptions.