Privacy Policy

Signivelle - Learn ASL teaches American Sign Language through short daily practice. This policy explains what the app keeps on your device, what it sends to our servers and to other services, why, and how you can delete it. It describes what the app actually does today.

What stays on your device

Your lessons, progress, streak, favorites, settings (daily goal, reminder time, handedness, sound and haptics choices) and your onboarding answers are stored only on your device. We do not receive them, and there is no account with a name, email address or password. Deleting the app removes them; the app's Delete my data control also removes them and asks our server to delete its records (below).

What our servers receive, and why

The app talks to our own backend (never directly to an AI provider). It receives:

• An install identifier and a public key. A random identifier and a cryptographic key are created on your device. Each request to our server is signed with the key so that copied or replayed traffic can be refused. We store the identifier, the public key, platform, app version and language.
• An anonymous Firebase sign-in and device attestation. The app signs in anonymously with Firebase Authentication and sends an App Check attestation (Apple App Attest or Google Play Integrity) so our server can tell that requests come from the genuine app. There is no name or contact detail attached.
• Subscription verification. When you subscribe or restore, the app sends the store's proof of purchase to our server, which checks it with Apple or Google. We store an encrypted reference to that purchase and the resulting status (active, expired, and its expiry) to decide whether AI features are available and to share one daily allowance across your devices. We never receive your payment details; Apple or Google handle payment.
• Usage counters and abuse limits. To enforce fair daily allowances we count AI requests per feature per day, and we keep short-lived request nonces to block replays. To rate-limit abuse we keep a keyed hash of the network address a request came from (never the address itself) for a short time.
• Reports. If you use Report on an AI answer, we store the feature, the reason you chose, the excerpt of the answer you reported (up to 600 characters) and your optional note so we can review it.

AI features

Signi (the tutor), the sentence translator (typed or spoken), practice scenarios, the daily plan and the fingerspelling photo check are powered by AI models reached through our backend. Before your first AI request the app asks for your permission and names what each feature sends:

• Typed text you enter into the tutor or translator, and the recent messages of the current chat.
• A short voice clip (up to 25 seconds) when you use the microphone in the translator; it is transcribed and translated.
• A photo of your hand (resized, with metadata removed) when you use the fingerspelling check. Please keep faces and other people out of the frame.
• Practice statistics (streak, goal, which signs you know or should review) for the daily plan.

Our server forwards this content to a third-party AI model provider for one-off processing and returns the answer. Voice clips and photos are processed in memory and are not saved or logged by us. We do not use your content to train models ourselves. AI answers can be wrong or incomplete: check important signs with Deaf teachers and community resources. You can turn AI permission off at any time in Me; the AI features then stop sending anything.

Diagnostics

The app uses Firebase Analytics for usage events (for example that a lesson was completed, without free text or your AI content) and Firebase Crashlytics for crash reports (device model, OS version and a stack trace). Google receives a Firebase installation identifier with these events and derives an approximate location (country or region) from the network address the request comes from. The app does not use or read your advertising identifier, and Google signals is off. These are processed by Google under its own terms.

Camera, microphone and notifications

The camera and microphone are used only when you tap the feature that needs them, after the system permission prompt. Reminder notifications are local to your device and only if you turn them on.

Sharing

We do not sell your data and we do not show ads. Data goes only to the services described here: Apple or Google (purchases), Google Firebase (anonymous sign-in, attestation, diagnostics) and the AI model provider used through our backend.

Deleting your data

In the app, open Me → Delete my data. This clears everything on your device and deletes our server records linked to your install. If you no longer have the app, use the web deletion form at https://signivelle.site/api/v1/public/deletion-request with your Data ID (shown in Me before you delete, and the same as the install identifier); we will delete the records for that identifier. Analytics and crash data held by Google are governed by Google's retention settings.

Children

The app is a general-audience learning tool and is not directed to children under 13. We do not knowingly collect personal information from children.

Changes and questions

We will update this page when the app's data practices change. For any question or request about your data, use the support page of this app; it reaches us without publishing a personal contact address here.