Privacy at Luftikus

Last updated: 25 October 2026

In short: Your weight, your food, your photos and your cycle stay on your iPhone. To get an answer from the AI coach, the app sends an excerpt of this to the AI. Our server does not store it, and the AI providers do not use it for training. Better speech recognition and the coach’s voice run via Google in an EU data centre. For duels and challenges, our server only knows your nickname and your daily points.

Controller

Philipp Knöbl, Leon-von-Berg (sole proprietorship)
Birkenstraße 8/13, 8501 Lieboch, Austria
Email: philipp.knoe@gmail.com

What is stored only on your iPhone

Profile and goals (name, sex, year of birth, height, starting and target weight)
Food diary with downsized food photos, weight history, water
Pantry, shopping list, favourite foods, recipes and the chat with the coach
Cycle data, if you use cycle protection (including data taken over from Apple Health)
Workouts, steps, active calories and your scale’s weight, if you connect Apple Health (read only, never written)
What the coach remembers about you (short notes that you can view and delete in Settings)
Tone and result of the motivation check, reminder settings

You can remove everything at any time under Settings › Delete everything and start over. This also deletes your account on our server (see “Deletion periods”).

AI coach

When you write to the coach, talk to it or send it a photo, the app sends your message, the photo if there is one and an excerpt of your data (goals, today’s entries, totals for the last few days, the latest weight values, pantry, shopping list, favourite foods, recipe titles, water, tone, motivation profile and your standing in a duel or challenge) via our server to Anthropic PBC (USA). Anthropic uses this to generate the answer. Our server does not store this content and does not log it.

Anthropic processes this data as a processor on the basis of its data processing agreement (Data Processing Addendum), does not use data from its programming interface (API) to train AI models, and generally deletes inputs and outputs within 30 days. The transfer to the USA is based on the EU Standard Contractual Clauses (Art. 46 GDPR). Details: anthropic.com/legal/privacy.

We are gradually switching the coach over to Claude via Google Cloud (Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland). Google will then process the requests in an EU data centre, likewise as a processor (Google Cloud Data Processing Addendum) and without training on your data. As soon as this applies, it will say so here.

The coach answers in your iPhone’s language (German, English, Italian, French or Spanish). For this, the app also sends the language.

The legal basis is your explicit consent (Art. 6(1)(a) and Art. 9(2)(a) GDPR), which you give when setting up the app. You can withdraw it at any time by no longer using the app and deleting your data.

The coach is an AI. It can make mistakes and is no substitute for medical or nutritional medical advice.

Our server

The server is hosted by ALL-INKL.COM in Germany and stores:

your access code only as a checksum (hash), not in plain text. Without a code, the app creates its own account during setup; it works just the same and contains no names or email addresses.
with a subscription: which subscription (monthly or yearly) and until when it runs. Payment is made only via Apple; we do not see any payment data or your Apple ID. For this, the app sends the purchase confirmation signed by Apple; we check the signature and store only a checksum of the subscription number from it, so that one subscription cannot run on many accounts at the same time.
a random device identifier, so that a code only runs on a few devices
the number of your requests per day and the costs incurred for them
for duels and group challenges: your nickname and your daily points. The server does not know your weight, food or cycle. Your opponent in a duel only sees whether you are ahead or behind; the group sees nicknames and points.
in a challenge’s group chat: your messages and photos with your nickname. Photos are downsized on the iPhone beforehand and stored without location data; only the members of the challenge can see them. Before sending, an AI (Anthropic) checks the message for insults and advertising; nothing is stored in the process. Reported messages are seen by the challenge’s admin and by us. Messages are deleted 30 days after the challenge ends. Anyone who breaks the rules can be excluded.

For technical reasons, the host stores access logs (including IP addresses) for a short time. To protect against abuse (e.g. trying out codes one after another), our server counts requests per sender. For this, it stores the IP address only as an irreversible hash and deletes the counters after one day at the latest.

Deletion periods

This is how long data stays on our server. Anything with a time limit is deleted automatically by the server’s daily check.

Deleting your account: Under Settings › Delete everything and start over, your account on our server is deleted immediately: code, device identifier, subscription assignment, counters, your chat messages and photos. You leave any running duels and challenges and the weekly league. Your previous daily points remain there without a name, so that the others’ rankings stay correct.
Not used for a long time: Accounts created by the app itself without a running subscription that have not been used for 24 months are deleted completely. If you open the app again after that, it quietly creates a new account. Your data on the iPhone is not affected.
Counters: requests and costs per day, seconds and characters for speech, and the days on which an account was active, after 24 months.
Group chat: messages and photos 30 days after the challenge ends, reported messages along with them.
Duels, challenges, weekly league: 90 days after the end, together with nicknames and daily points.
Bans in the group chat: after 12 months.
Abuse protection: counters per sender after one day at the latest.

The anonymous usage counters (day, name of a feature, count) do not belong to any account and are kept. Deleted data may still be contained in our host’s backups until the backup is overwritten.

Dictation and voice

When you dictate, Apple’s speech recognition converts your speech into text. From iOS 26 onwards, this happens on the iPhone itself; with older versions, Apple may process the recording on its servers for this purpose (see Apple’s privacy information on Siri and Dictation).

With the coach subscription and during the welcome week, the app also uses the more accurate speech recognition and the natural voice of Google Cloud (Google Ireland Limited, Dublin). For this, when you send, the audio recording of your dictation or the text of the coach’s answer goes via our server to Google, where it is converted into text or speech in an EU data centre. Our server stores neither the recording nor the text, only how many seconds or characters were used per day (for limits and costs). Google processes the data as a processor under the Google Cloud Data Processing Addendum and does not use it for training. If Google cannot be reached, Apple takes over on the iPhone. Here too, the legal basis is your explicit consent given during setup.

Barcode

When you scan a barcode, the app looks up the nutritional values at Open Food Facts, a free food database (Open Food Facts, France). Only the barcode number is transmitted, and for technical reasons also your IP address, but no data about you or your food. The camera image stays on the iPhone.

Apple Health and notifications

If you allow it, the app reads workouts, steps, active calories and your scale’s weight from Apple Health so that your daily budget matches your training, and, if you wish, your period days for cycle protection. It does not write anything to Apple Health. The data stays on the iPhone; only summaries (e.g. “today 45 minutes cycling, 380 kcal”) go to the coach with a request. Reminders are local notifications on your iPhone; no data is transmitted for them.

Anonymous usage statistics

So that we can see whether the app helps and where we need to improve it, the server counts on which days an account uses the app (only the date) and how often certain features are used, e.g. “Food logged via barcode” or “Goal reached”. These counters contain only the day, name and count, no link to you and no content. You can turn them off in Settings under “Data”. The legal basis is our legitimate interest in a working, better app (Art. 6(1)(f) GDPR).

No advertising, no third-party tracking

Luftikus does not use any third-party analytics or tracking services and does not pass on or sell any data. Sponsored challenges are clearly labelled as advertising. Sponsors do not receive any data about you.

Your rights

You have the right of access, rectification, erasure, restriction of processing, data portability and objection, as well as the right to withdraw your consent. You can also lodge a complaint with the Austrian Data Protection Authority (Datenschutzbehörde): dsb.gv.at.