Last updated 2026-09-24

Privacy policy

In short: Taiyo has no accounts. Your profile, your sun sessions, supplements, food and blood tests are stored only on your iPhone. To show the UV index where you are, the app sends an approximate location (rounded to about 1 km) to our server, which does not link it to you. We do not sell data, show ads or use tracking or analytics tools.

1. Who is responsible

• Owner: José Antonio Neto Suárez (Utropia)
• Tax ID: ES29607219D
• Address: C/ Manuel Vela 37, 13, 21440 Lepe, Huelva, Spain
• Contact: hello@utropia.es

2. Data that stays on your device

Everything you enter in Taiyo is stored in the app's own database on your iPhone and is never sent to us:

• Your profile: skin type, year of birth, whether you are pregnant or breastfeeding, and your daily goal.
• Your logs: sun sessions (time, duration, clothing, sunscreen), supplements, food and the vitamin D estimates for them.
• Blood test results you choose to save.
• Your place (if you pick a city), reminders and preferences.

Some of this is health information. It stays on your device and we never receive it. It is removed when you delete the app or use You › Delete all my data. If you back up your iPhone to iCloud or a computer, Apple includes it in that backup according to your own settings.

3. Location and the UV index

With your permission, Taiyo uses your location while the app is in use to find the UV index where you are. Before anything leaves your device, the coordinates are rounded to two decimals (about 1 km). The app then asks our server (api.gettaiyo.com) for the UV of that area for a given date and time zone.

• Our server keeps UV data per map area (not per person) so that it can answer faster. It never stores who asked for it.
• To get the forecast, our server asks the Norwegian Meteorological Institute (MET Norway) for the same approximate area. No data about you is sent.
• If you search for a city by name, the search is done by Apple's geocoding service on your iPhone.
• If you do not allow location, you can choose a city and Taiyo will use that instead.

4. Technical data our server receives

• Installation identifier. A random code created on your iPhone the first time the app runs. It does not identify you or your device model. It is used only to limit abuse (rate limiting) and is kept, in a one-way hashed form, for a few minutes at most.
• Server logs. Like any web server, ours records the IP address, time and requested address of each request. Coordinates in our application logs are rounded further, to about 11 km. We keep logs for up to 14 days for security and to fix problems.

5. Apple Health (optional)

If you connect Apple Health, Taiyo can read dietary vitamin D recorded by other apps and write the supplements and food you log in Taiyo. It never writes sun estimates. This data stays on your device and in Apple Health. We never receive it and it is not used for advertising or marketing. You can turn access off at any time in the Health app settings.

6. Notifications

Reminders are scheduled locally on your iPhone. We do not use push notification servers and we do not know which reminders you set.

7. Purchases and subscriptions

Payments are handled by Apple through your Apple ID. We never see your payment details. To check whether you have Taiyo Pro, the app uses RevenueCat, which processes your App Store receipt and an anonymous app user identifier created by the app. RevenueCat acts as our service provider (processor). Its servers may be in the United States; the transfer is covered by the EU standard contractual clauses and, where applicable, the EU–US Data Privacy Framework.

8. What we do not do

• No accounts, no email sign-up and no social login.
• No advertising, no selling or sharing of data, and no data brokers.
• No analytics, tracking, fingerprinting or advertising identifiers.

9. Legal bases (GDPR)

We process the approximate location and technical data to provide the service you ask for (Art. 6(1)(b) GDPR) and, for security logs, on the basis of our legitimate interest in keeping the service safe (Art. 6(1)(f)). Health information you enter stays on your device and is not processed by us.

10. Your rights

You have the right to access, rectify, erase, restrict and object to the processing of your data, and to data portability. Because we do not hold personal data linked to you, most of these rights are exercised directly in the app (for example, Delete all my data). For anything else, write to hello@utropia.es. If you are in the EU, you may also complain to your data protection authority; in Spain, the AEPD.

11. Children

Taiyo is not directed at children under 16 and we do not knowingly collect their data.

12. Changes

If we change how Taiyo handles data, we will update this page and the date above. For material changes, we will let you know in the app.