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Privacy policy

Version 2 · Effective 2 September 2026

At a glance. UV Tracker has no advertising. Signing in with Google and syncing your skin profile across devices are both entirely optional and off by default. Your approximate location is sent to a weather service to fetch a UV forecast. Photographs of the sky and of your skin are processed on your device and deleted immediately — they are never uploaded, sign-in or not. Everything else stays on your phone unless you turn sync on.

This policy describes the UV Tracker mobile application ("the app"), published by the UV Tracker project ("we", "us"). It describes the app as it exists today. If we add advertising, this policy will be updated and re-versioned before that ships, and the change will be noted in Changes to this policy.

1. What the app collects

The table uses the categories of Google Play's Data Safety section, so what you read here is what the store listing declares.

Location — approximate locationCollected

Shared?: Yes, to Open-Meteo
Purpose: To fetch the UV index forecast for where you are
Where it goes: Sent to Open-Meteo without any identifier. Not stored by us; the last reading is kept on your device.

Photos and videos — camera frames of the skyNot collected

Shared?: No
Purpose: To estimate cloud cover and refine the UV reading
Where it goes: Analysed as they arrive. Never written to storage, never uploaded.

Photos and videos — a photograph of your inner forearmNot collected

Shared?: No
Purpose: To estimate your skin tone
Where it goes: Written to a temporary file by the camera, read, then deleted immediately. Never uploaded — this holds whether or not you are signed in or sync is on.

Health and fitness — your estimated skin type and skin conditionCollected if you opt in

Shared?: Only if you turn on "Sync skin profile" in Settings, and only with Google Firebase (our cloud database), not with any other party
Purpose: To calculate a safe sun time for you rather than an average person, and — if you opt in — to make that estimate available on a second device
Where it goes: Stored on your device by default. With sync on, your skin type and skin condition (not the photo, not a location) are also stored in our Firestore database, readable only by your signed-in account. Turning sync off, or deleting your account, deletes that copy.

Account info — name, email address and profile photoCollected if you sign in

Shared?: Only if you choose to sign in with Google; shared with Google Firebase Authentication to keep you signed in
Purpose: To identify your account, so a skin profile you opt to sync can be tied to you and to no one else
Where it goes: Held by Firebase Authentication. You can sign out or delete your account from Settings at any time; see section 2.

App activity — your last UV reading and settingsNot collected

Shared?: No
Purpose: To show a value when offline and remember your preferences
Where it goes: Stored only on your device.

Diagnostics — crash logs and device informationCollected

Shared?: Yes, with Google Firebase Crashlytics
Purpose: If the app crashes, technical information helps us find and fix the problem
Where it goes: Device model, OS version, app version, and a log of recent in-app events are sent to Firebase Crashlytics. Crash reports never include your location or photos. You can turn this off at any time in Settings → Share crash reports.

"Collected" follows Play's definition: data transmitted off your device. Data that stays on your phone, or is processed and discarded, is not collected. If you never sign in and never turn on skin-profile sync, the app collects only your approximate location and, unless you opt out, crash diagnostics — it does not collect your name, email address, skin data, or any account identifier. It contains no advertising SDK, no analytics SDK, and no third-party tracking.

2. Signing in and skin-profile sync

Signing in and syncing are both optional. The app works fully without either — a signed-out user keeps everything on their device, exactly as described in section 1.

Signing in with Google (Settings → Account) creates an account identified by your Google name, email address and profile photo, handled by Google Firebase Authentication. This alone does not send your skin data or readings anywhere; it only identifies you, so that a skin profile you separately choose to sync can be tied to your account and to no one else.

Syncing your skin profile (Settings → Account → "Sync skin profile", once signed in) is a second, separate choice, off by default even after you sign in. When it is on, your estimated skin type and skin condition — never a photograph, never a location — are saved to our Firestore database (Google Cloud, hosted by Firebase) so a second device signed in to the same account can use them. Only your account can read or write that document; nobody else, including us, can browse it outside normal database administration. Turning the switch off deletes the stored copy immediately, and deleting your account (Settings → Delete account) deletes it first, before the account itself is removed.

Signing out leaves both your local data and, if sync was on, the stored copy untouched — sign back in to pick up where you left off. Deleting your account removes your Google sign-in from the app and, per above, any synced skin profile; your on-device readings are unaffected, since they were never tied to the account in the first place.

3. Location, specifically

The app requests location permission only while it is in use, and requests coarse accuracy — the UV index varies over roughly ten-kilometre areas, so a precise fix is unnecessary. Your coordinates are sent to Open-Meteo, an open weather API, to retrieve the forecast. Their handling of that request is governed by Open-Meteo's terms and privacy statement. We send no identifier with the request, so it is not linked to you or your device.

If you decline location permission, the app cannot fetch a local forecast. Nothing else is affected.

4. Camera and images

The camera is used for two features: reading cloud cover from the sky, and estimating skin tone from a photograph of your inner forearm.

Sky frames are analysed as they arrive and are never saved. The forearm photograph is written to a temporary file by the operating system's camera, read into memory to measure its average colour, and then deleted straight away — including when the reading fails. Neither image is uploaded, transmitted, or retained, whether or not you are signed in.

What is kept is the result: an estimated skin type and a colour measurement, stored on your device, and additionally in our database if you have separately opted in to sync (section 2).

5. Where your data is stored

By default, all data the app keeps is held in your device's private application storage; we operate no servers and hold no copy of it. If you sign in, your account details are held by Firebase Authentication; if you additionally turn on skin-profile sync, your skin type and condition are also held in our Firestore database. Uninstalling the app removes on-device data permanently; it does not, by itself, delete a signed-in account or a synced skin profile — sign in on the reinstalled app and use Settings to sign out or delete the account for that.

We do not sell, rent, or share your data. Network requests the app can make are: the forecast lookup described in section 3; if you sign in, authentication with Google Firebase Authentication; if you additionally turn on sync, reading and writing your skin profile to Firebase; and, unless you opt out, crash diagnostics to Firebase Crashlytics (section 1). None of these share data with any party beyond Google's Firebase platform, which we use as our infrastructure provider, not as an independent recipient of your data.

7. Your rights and choices

Revoke permissions — location and camera access can be withdrawn at any time in your device settings.
Sign out or delete your account — available at any time in Settings; deleting your account also deletes a synced skin profile first, per section 2.
Turn sync off — Settings → "Sync skin profile"; this deletes the stored copy immediately without touching your sign-in or your on-device data.
Delete your data — clearing the app's storage or uninstalling it erases everything held on your device, immediately and permanently.
Access and portability — for data that never leaves your device, there is no copy for us to provide; for a synced skin profile, contact us (section 11) and we will retrieve or erase it on request.

If you are in the EU, UK, or another region with comparable law, the lawful basis for processing is your consent, given by granting the relevant permission or opting in to sign-in and sync, and withdrawn by revoking it, signing out, or turning sync off.

8. Children

UV Tracker is not directed at children under 13, and we do not knowingly collect data from them, including through Google sign-in. If you believe a child has created an account, contact us and we will delete it.

9. Not a medical device

The app's readings are estimates derived from public forecast data and a phone camera. They are not a medical device and not medical advice. Do not rely on them for diagnosis or treatment of any condition.

10. Changes to this policy

If the app's data handling changes, this page is updated and its version and effective date raised before the change reaches you. Material changes — for instance introducing advertising — will also be surfaced in the app itself.

11. Contact

Questions about this policy, or a request to access or delete a synced skin profile: privacy@uvstracker.com

Version history

Version 1 · 28 August 2026: Initial policy. No accounts, no advertising, no analytics; coordinates to Open-Meteo only; camera images processed on-device and deleted; skin type on-device.
Version 2 · 2 September 2026: Adds optional Google sign-in (name, email, profile photo, via Firebase Authentication) and optional cross-device skin-profile sync (skin type and skin condition only, never a photo or location, via Firestore), both off by default; account deletion also deletes a synced skin profile first.
Planned: Version 3: Will be published before the first advertisement is shown. Adds the advertising identifier and the consent choices offered in the app.