Privacy Policy — Asidu

Effective date: 2026-09-18 · Last updated: 2026-11-04

Asidu ("the App") is developed under the brand Studio Flysch. Studio Flysch is a brand of:

Nicolas Burri Studio GmbH
Flüelastrasse 16, c/o Genossenschaft Atelier Uto, 8048 Zürich, Switzerland
UID CHE-470.128.392, commercial register of the Canton of Zürich
Represented by Nicolas Burri, managing director
Contact for all privacy matters: [email protected]

We are the controller for the processing described here. This policy explains what data the App and the website asidu.app process, why, where, for how long, and what rights you have. Asidu is offered in Switzerland and is intended for adults (18 and over).

1. Summary

• No account. You don't register or log in, and the App doesn't ask for your name or e-mail address.
• Your diary stays on your iPhone. Food entries, weight, profile, targets and everything the App calculates are stored only on your device (and in your own iPhone backup, if you use one).
• Apple Health data is processed on your device. It is not sent to our server as raw data. One exception you start yourself: for an AI meal suggestion, the App sends the calories, protein and fat you have left for the day, rounded — values calculated partly from Health data (Section 5.1).
• AI features send your input to an AI provider in the USA — only after you allow it. Text, photos, PDFs and recipe ingredients you submit go via our server to Anthropic. Anthropic does not train on them and deletes them within 30 days (exceptions in Section 6).
• Pseudonymous identifiers, not anonymous ones. For usage limits, AI budgets and credits our server works with random identifiers and Apple transaction numbers. We can't see who you are, but these identifiers single out a device, a purchase or a credit account, so they count as personal data (Sections 5.3–5.5).
• No advertising, no tracking across apps, no sale of data.

2. Data stored only on your device

• Profile: year of birth, height, sex, body-fat percentage (optional), goal, target rate, dietary targets and preferences.
• Nutrition log: meals, ingredients, quantities, nutritional values, times, notes, favourites and recurring-meal rules.
• Photos you add to a favourite: stored as a small image on your iPhone and in your backups, and as an even smaller copy on your paired Apple Watch. They are never sent to us or to any other service.
• Weight entries you enter in the App.
• Calculated values: energy expenditure estimates, calibration factors, daily carryover, recovery signals and their history.
• Settings, reminders, dashboard layout, energy-source settings, skipped days and vacation periods.
• Supplement reminders and the days you marked them as taken (kept for 14 days).
• A cache of food products you scanned or searched.
• If calendar access is on: which calendars you selected, and a cache of recognised event titles.
• If you use Recovery Mode: the training-break periods you log, their dates and an optional note.
• AI requests that could not be sent yet (for example while offline), including the text or downscaled photo, for up to 14 days or until they are sent or you discard them.
• Your acceptance of the Terms of Use (version and date), your answer to the age question and whether you allowed AI features.
• If you connect Intervals.icu: the access key (in the iPhone keychain only), the name of the connected account, your import/export settings and the imported planned workouts.
• If you use the Apple Watch app: your iPhone sends a summary of today's values and your favourites (name, amount, calories) directly to your paired watch via Apple's WatchConnectivity. When you log a favourite on the watch, the watch sends only which favourite and meal you chose back to your iPhone. When you describe a meal on the watch, the watch sends the text to your iPhone, which handles it like typed text (Section 5.1); dictation is provided by Apple.

You control this data: export it (Profile → Data → Export Backup), import it, or delete everything (Profile → Data → Delete All Data). We have no copy. A coach report (Profile → Data → Share with Coach) is created on your device and leaves it only if you share it yourself. Your iPhone backup (iCloud Backup or computer) includes this data; that backup is controlled by you and Apple. The Intervals.icu access key is not included.

3. Apple Health

With your permission, the App reads: active and resting energy, workouts (type, duration, energy, and which app or device recorded them), body mass, body-fat percentage, height, biological sex, date of birth, heart rate variability, resting heart rate, sleep, VO₂ max and — only if you turn on cycle correction — menstrual flow.

With your permission, the App writes: dietary energy, protein, carbohydrates, fat and caffeine (one value per meal), and body mass you record in the App. Meals estimated by AI are written only after you confirm, correct or edit them.

Health data is processed on your device to calculate targets, trends and recovery signals. Raw Health data is never sent to our server, to Anthropic or to any other third party, never used for advertising and never sold. Values derived from it leave the device only in two cases you start yourself: an AI meal suggestion (remaining calories, protein and fat for the day, Section 5.1) and the optional Intervals.icu export of daily nutrition totals from the entries you log in Asidu (Section 5.6).

You can revoke any permission in iOS Settings → Privacy & Security → Health → Asidu.

3.1 Cycle correction (optional, off by default)

If you turn on cycle correction (Profile → Training → Cycle Correction), the App reads menstrual flow from Apple Health. It looks back at your past cycles, estimates how much water you typically retained in the second half of a cycle and subtracts it from your weigh-ins before calculating your weight trend, weekly outlook and calibration. It does not predict your cycle, ovulation or fertility, and it doesn't change your calorie or macro targets directly.

Cycle data is processed only on your device and never leaves it. A coach report uses the corrected weight trend but does not mention your cycle. Cycle data is health data that we process only with your explicit consent, which you give by turning the feature on and allowing the permission; you can withdraw it at any time by turning it off or revoking the permission.

4. Calendar

With your permission, the App reads title, start time and duration of events in the calendars you select (Profile → Training Calendar) — none by default, and never notes, locations or attendees.

Titles are recognised on your device first. Only a title the App can't recognise itself is sent once — with its duration — via our server to Anthropic to find out whether it is a workout. Titles that look medical (for example doctor, physio, therapy, clinic, hospital, Arzt, Therapie) are never sent. You can turn this off under Profile → Privacy ("Recognise unclear titles online"); unclear titles then stay unrecognised. The result is stored on your device.

5. What leaves your device, and why

Requests that are not sent directly from your iPhone go to our server on Cloudflare Workers (Section 6), which forwards them. Our server does not store or log the content of your requests.

5.1 AI features (consent required)

Before you use an AI feature for the first time, the App asks for your consent ("Before you use AI"). You can withdraw it at any time under Profile → Privacy; AI features then stop until you allow them again.

What is sent via our server to Anthropic, PBC (USA):

Text the App can match in its built-in Swiss food database is never sent.

A PDF or photo can contain health information (for example an export from another nutrition app). Only upload what you want analysed, and nothing that contains other people's data.

No name, e-mail address, Apple ID, profile, diary or raw Health data is sent, and Anthropic doesn't receive any of our identifiers.

5.2 Food search and barcodes

• FatSecret Platform API (FatSecret, Australia): your search term or barcode, sent by our server. FatSecret receives neither your device identifier nor your IP address.
• Open Food Facts (association, France): barcodes are looked up directly from your iPhone, so Open Food Facts sees your IP address and the barcode, as with any web request.
• Swiss Food Composition Database (Federal Food Safety and Veterinary Office FSVO): built into the App, no request.

5.3 Subscriptions, Lifetime and AI budget

For AI features and calendar recognition, the App sends Apple's signed purchase record. Our server verifies it against Apple's certificates and uses the original transaction number Apple assigns to your purchase — not your name or Apple ID — to keep your AI budget: per number, the cost of your AI requests per day and month (or trial), the number of requests and the time of the last request. With Lifetime it counts calendar recognitions per month (at most 50). We can't link the number to you as a person; Apple can, under Apple's privacy policy.

5.4 AI credits

When you first buy credits, the App creates a random credit-account identifier, stores it in your keychain (and, if iCloud Keychain is on, in iCloud Keychain, so your other devices with the same Apple ID share the balance) and passes it to Apple as "app account token". Our server stores per credit account: the balance, the transaction numbers of credit purchases (so each is credited once and refunds can be applied), daily totals and, for 60 seconds, a one-way checksum of each request to stop accidental repeats. No request content is stored. The credit-account identifier is never sent or stored together with the device identifier.

5.5 Device identifier

To limit food search, barcode lookups and Intervals.icu connection attempts, and for AI requests without a purchase record or credit account, the App sends a random identifier that it creates on first use and stores in your keychain. Our server counts requests per identifier and day and keeps the counters for 48 hours. Requests without an identifier are rejected; we don't use your IP address as a substitute.

The identifier stays in the keychain when you delete the App and moves to a new iPhone with an encrypted backup. "Delete All Data" (Profile → Data) and "Reset device identifier" (Profile → Privacy → Server data) replace it with a new random one.

5.6 Intervals.icu (optional, off by default)

If you connect your Intervals.icu account (Profile → Training → Intervals.icu), the App exchanges data with Intervals.icu directly from your iPhone.

• Connecting: you sign in on Intervals.icu and choose what Asidu may access. To turn the one-time code into an access key, the App sends it once to our server, which adds Asidu's app credentials, forwards it to Intervals.icu and returns the key to your iPhone. Our server doesn't store or log the code or the key.
• Import (if enabled): your planned workouts for today and the next 7 days (date, time, sport, duration, distance, planned load, race category), about once an hour or when you tap Sync now. They stay on your device. Calorie values from Intervals.icu are not used.
• Export (if enabled): for completed days, your daily totals of energy, carbohydrates, protein and fat, calculated only from entries you logged in Asidu, are written to the wellness data of your own Intervals.icu account. Data read from Apple Health is never sent.
• Disconnecting deletes the key and all imported data from your device and asks Intervals.icu to revoke access. Exported data stays in your Intervals.icu account under Intervals.icu's privacy policy.

5.7 Notifications and analytics

Reminders are local notifications; no data leaves your device. The App contains no analytics, advertising or crash-reporting SDK. If you share analytics with app developers in iOS settings, Apple gives us aggregated statistics.

6. Recipients

7. Legal bases

• Switzerland (FADP): we process data in line with the principles of Art. 6 FADP. Health data — cycle data, and a PDF or photo you upload that contains health information — leaves your device only with your explicit consent.
• Users in the EU/EEA or UK, if the GDPR or UK GDPR applies: providing the features you use (Art. 6(1)(b)); consent for AI features, cycle correction, calendar recognition and the waitlist (Art. 6(1)(a), for health data Art. 9(2)(a)); our legitimate interest in preventing abuse and operating securely — usage limits, budgets, error logs, refund checks (Art. 6(1)(f)); legal obligations (Art. 6(1)(c)).

8. Information stored on your device (Art. 45c Telecommunications Act)

The App stores two identifiers in your device's keychain: the device identifier (Section 5.5) and, once you buy credits, the credit-account identifier (Section 5.4). They are needed for usage limits and for your credit balance. You can reset the device identifier at any time under Profile → Privacy → Server data; the credit-account identifier stays because it holds purchased credits. If you don't want these identifiers to be used, don't use food search, barcode lookup, AI or credits; all other features work without them.

9. Retention

• Data on your device: until you delete it or the App.
• Usage counters (device identifier): 48 hours.
• AI budget records: 60 days after the last AI request.
• Block after a refund or revocation: until the subscription would have expired, plus 30 days.
• Credit account: as long as there is a balance, then 24 months after the last purchase or use.
• Transaction numbers of credit purchases: 24 months.
• Request content on our server: not stored. At Anthropic: see Section 6.
• Server error logs: a few days, at most 7.
• Waitlist: until you unsubscribe, at the latest 12 months after the public launch.
• Support e-mails: until your request is resolved, at the latest 24 months.

10. Automated decisions

If Apple tells us that a subscription or credit purchase was refunded or revoked, our server automatically stops AI access for that subscription, or removes the refunded credits from the remaining balance (the balance never becomes negative). No person reviews this beforehand. You can ask us at [email protected] to explain the decision and to have it reviewed by a person.

11. Your rights

You have the right to information, rectification, deletion, restriction, data portability and objection, and you can withdraw consent at any time with effect for the future.

• Data on your device: exercise these rights yourself — export, edit or delete under Profile → Data.
• Data on our server: we don't know who you are, so we need the identifier. Profile → Privacy → Server data shows your device identifier and credit-account identifier, lets you copy them and opens a prepared e-mail to [email protected] ("Request information" or "Request deletion"). Transaction numbers are in your Apple purchase history.
• Complaints: Federal Data Protection and Information Commissioner (FDPIC), Bern, www.edoeb.admin.ch. If the GDPR applies to you, you can also complain to the supervisory authority in your country.

12. Security and breaches

Connections are encrypted (HTTPS). If a security breach affects your data and you need to act, we will inform you in the App and on asidu.app, and notify the FDPIC where required.

13. Minimum age

Asidu is only for people aged 18 or over. The App asks for your year of birth before you start.

14. TestFlight

If you test a beta version through Apple's TestFlight, Apple shares with us your tester e-mail address (or the public link you used), device model, OS version, crash reports and the feedback you choose to send, under Apple's TestFlight terms. We use them only to improve the beta and delete them when the beta ends.

15. Support e-mails

If you write to [email protected], we process your e-mail address, your message and any attachments to answer you. Mail is forwarded by Cloudflare Email Routing to our e-mail provider. Please don't send health information by e-mail unless your request needs it.

16. Website asidu.app

• Hosting: Cloudflare Pages. Cloudflare processes IP address and request time to deliver the site securely. No cookies, no analytics, and no fonts or scripts from third parties.
• Waitlist: if you sign up, our server sends your e-mail address and optional answers (main sport, weekly training hours, phone type), the sign-up date and the source you came from (for example "instagram") to Brevo. You then receive a confirmation e-mail; only after you confirm are you on the list (double opt-in). To prevent abuse, our server keeps a one-way hash of your IP address for 24 hours, never the address itself. We use the list only to send you beta and launch information. Every e-mail has an unsubscribe link, and you can write to [email protected] to be removed. Legal basis: your consent.

17. Changes

We update this policy when features change and show material changes in the App. The current version is available at https://asidu.app/privacy and in the App under Profile → Legal.