Helios privacy policy
Last updated: 11 October 2026
Helios is an Android app published by Tarko Evolution that shows the UV index for a city you choose and estimates how long your skin can stay in the sun. This policy explains what the app does with data.
Data sent to our servers
To fetch the UV index and weather forecast, the app sends our servers the approximate coordinates of the city you chose (rounded to about one kilometre). Our servers obtain the forecast from a weather data provider, which receives only those approximate coordinates. You can type the city, or tap “Use my location”: only then the app asks for the approximate location permission (never precise location, never in the background), reads the phone’s approximate position once and saves it on your device as your city, exactly like a city you type.
Our servers keep only what is needed to operate the service and protect it from abuse, for a limited time, and never in a form that identifies you.
Data stored on your device
Your skin type, sunscreen choice, locations, settings, timer, the history of UV you received during timer sessions and the downloaded forecast are stored only on your device, in the app’s private storage. There is no user account. Uninstalling the app deletes all of it.
Support messages
If you write to us from Settings > Support, the app sends our servers the email address you type, your message, the app version, your Android version and phone model, and the app language. Our servers forward them, without storing them, to our internal support channel on Telegram (a messaging service run by Telegram), where we read them so we can reply to you by email. We keep the message only as long as we need to answer you and delete it within 12 months at the latest. Nothing is sent unless you press Send.
App usage analytics
The app uses Google Analytics for Firebase, a service run by Google, to understand how the app is used so we can improve it. It records app activity such as steps and screens reached (for example, finishing the setup, opening the Helios Pro screen, starting a purchase or finishing a sunscreen timer session), in-app purchases made through Google Play, and technical information such as device model, Android version, app version, language and a coarse region derived from the connection. It is linked to an app instance identifier generated by Firebase for analytics, not to your name, email or Google account. The app does not collect the advertising identifier and does not send your city, skin type or any text you type to analytics. Google processes this data on our behalf under its own terms and privacy policy (policies.google.com/privacy). Analytics data is kept for up to 14 months.
Crash reports
To find and fix errors, the app uses Firebase Crashlytics, a service run by Google. When the app crashes or stops working, it sends a crash report with the error and where it happened in the app, the app version, device model, Android version, the screen orientation and free memory and storage at that moment, and a random identifier for this installation. Crash reports do not include your city, skin type, name, email or anything you type. We process them on the basis of our legitimate interest in keeping the app working and correcting its errors. Google processes this data on our behalf under its own terms and privacy policy (policies.google.com/privacy). Crash reports are kept for up to 90 days.
Data we do not collect
Apart from support messages you choose to send and the usage analytics and crash reports described above, we do not receive your name, email, phone number, precise location or advertising identifier. The app contains no advertising.
Purchases
Helios Pro is purchased through Google Play, which handles the payment and tells us only whether the purchase is active. Subscription management and refunds are handled by Google Play.
Permissions
- Internet: to fetch the forecast for the chosen city.
- Notifications: only if you start the sunscreen timer, turn on alerts or show the UV in the notification bar. You can withdraw the permission at any time from Android settings.
Data deletion
Helios has no user accounts, so there is no profile tied to your identity to delete. Usage analytics and crash reports are tied only to an app instance identifier and expire automatically after 14 months and 90 days respectively; uninstalling the app resets that identifier. Apart from support messages, analytics and crash reports, the only data our servers receive is the approximate coordinates of the city you choose in the app, used to fetch the forecast; it is deleted automatically within 24 hours and never kept longer. Data stored on your device (skin type, sunscreen, locations, settings, timer, UV history) is deleted immediately when you uninstall the app.
To ask us to confirm that no data linked to you remains on our servers, write to info@tarkoevolution.com, naming the app (Helios). We will reply within 30 days.
Children
The app is not directed at children under 13 and does not knowingly collect data from them.
Changes
If a future version changes what the app does with data, this page will be updated before that version is published and the date above will change.