Last updated: 23 August 2026 · Applies to the Sayly iOS app and the Sayly backend service.
Sayly is operated by StarNova ("we", "us"). For any privacy question or request, contact us at vdnhan97@gmail.com.
Sayly does not have user accounts. On first launch the app asks our server for an anonymous visitor ID — a random UUID stored on your device. Everything you do in the app is associated with that ID and nothing else. We never collect your name, email address, phone number, postal address or date of birth.
To keep your streak and history from being lost or farmed when the app is reinstalled, the app also computes a device fingerprint using the open-source FingerprintJS library and sends it once, when the visitor ID is created. The fingerprint is derived from general device and browser characteristics; it is used only to recognise the same device and map it back to the same anonymous visitor.
| Data | Why | Kept |
|---|---|---|
| Anonymous visitor ID (random UUID) | Identifies your practice history, streak and entitlement without an account | Until you ask us to delete it |
| Device fingerprint (FingerprintJS visitor id) | Recognises the same device after a reinstall so your streak survives; limits abuse of the free allowance | Until you ask us to delete it |
| Voice recordings of your answers | Transcribed by a speech-to-text provider so the AI can review your speaking | Deleted after processing and history retention; see section 6 |
| Transcripts and typed answers | Shown back to you in your learning history; used to target the next day's question at your weak points | Until you ask us to delete it |
| AI review results (score, corrections, mistake tags) | Your history, streak and insights | Until you ask us to delete it |
| Time zone and preferred feedback language | Decides when your "day" rolls over and what language the feedback is written in | Until you ask us to delete it |
| IP address | Rate limiting and abuse prevention only. Not stored alongside your answers. | Short-lived logs |
| Purchase and subscription status | Unlocks Pro. We receive the status, never your card details. | While the entitlement is active plus records required for accounting |
| Anonymous product analytics events | Understanding which parts of the app work; see section 5 | Per Google Analytics retention settings |
Sayly does not collect contacts, photos, location, health data, advertising identifiers (IDFA) or browsing history, and does not track you across other companies' apps or websites.
The app asks for microphone access only so you can record a spoken answer. Recording starts when you tap to record and stops when you tap to stop. The recording is uploaded to our storage, transcribed and reviewed, and the result is shown to you. You can use Sayly without the microphone by typing your answer instead.
If analytics is enabled in a build, Sayly uses Google Analytics for Firebase (Google Analytics 4) to count anonymous product events such as "onboarding completed", "answer submitted", "paywall shown" and "screen viewed". The identifier sent to Google is your anonymous visitor UUID, alongside an app instance identifier and the vendor identifier (IDFV) that the Firebase SDK generates for this install. Both are reset when you delete the app. We never send transcripts, recordings, review text, names or email addresses to Google. Sayly does not use the advertising identifier — the app is built against the Firebase SDK variant that has no IDFA capability at all — and therefore does not show the App Tracking Transparency prompt, and does not track you across other companies’ apps or websites.
We share data only with the service providers needed to run the app:
We do not sell your data, we do not share it with data brokers, and we do not use it to build advertising profiles.
Data is stored on servers operated on our behalf and transmitted over HTTPS. Access is restricted to the systems and people that need it to operate the service.
Sayly is not directed at children under 13, and we do not knowingly collect data from them. If you believe a child has used the app and provided data, email us and we will delete it.
If this policy changes materially we will update this page and change the date at the top. Continuing to use Sayly after a change means you accept the updated policy.