Effective date: September 28, 2026
Bissbilanz is a personal calorie and macro tracking app built by a solo hobbyist developer. This policy explains what data the app collects, how it is used, and how you can control it. It covers the web app at bissbilanz.orellbuehler.ch and the Bissbilanz apps for Android and iOS (including the widgets and the Apple Watch app).
The data controller is Orell Bühler, Switzerland. For any privacy question or request, contact me@orellbuehler.ch.
When you use Bissbilanz with an account, the app stores the following:
The app does not collect location data, advertising identifiers, or contact lists.
The mobile apps use the camera to scan barcodes and to read nutrition labels. Barcode and label recognition run on your device; camera frames are not uploaded. Only a scanned barcode number is sent to the server (and to Open Food Facts, see below) to look up the product. Photos you explicitly take for foods, recipes or AI meal estimation are uploaded to the server.
The Android and iOS apps can be used without an account. In that mode your data stays in the app's local database on your device and nothing is sent to the Bissbilanz server. On iOS, the local database is mirrored to your private iCloud database so it is available on your other Apple devices; Bissbilanz cannot access it. Barcode and food searches are sent directly to Open Food Facts, and crash reports are still sent to Sentry (see below). If you later sign in, your local data is migrated to your account once.
On iOS you can optionally connect Apple Health to import weight and sleep data into your log and to write your logged weight, sleep and nutrition back to Health. Health data is read and written only on your device with your permission; imported values become normal entries in your log. Bissbilanz never shares Health data with third parties and does not use it for advertising.
On Android you can optionally connect Health Connect. Bissbilanz only accesses it after you grant the individual permissions in the Health Connect permission dialog, and you can revoke them at any time in Health Connect or in Android settings. The app requests:
Health Connect data is used only to show you your own weight, sleep and nutrition inside the app. Values you import become normal entries in your log and are stored the same way as entries you type in yourself; they are deleted when you delete the entry or your account. Health Connect data is never sold, never used for advertising, never shared with third parties, and never sent to Sentry or any analytics service. If you revoke the permissions, the app stops reading and writing immediately; entries already imported stay in your log until you delete them.
Your data is used solely to provide the food tracking functionality of the app: showing you what you ate, calculating your daily totals, charting trends, and tracking your progress against your goals.
Your data is never sold, never used for advertising, and never shared with third parties except the services listed below.
You can connect an AI assistant of your choice to your account via the Model Context Protocol (MCP). This only happens if you explicitly authorize it; the assistant then accesses your data with a token you can revoke at any time. What the assistant's provider does with data it reads is governed by that provider's own privacy policy.
When you connect Claude or ChatGPT, the data the connector requests for your conversation (for example your food log, goals, weight, sleep or supplements, and meal photos you queued for the assistant) is processed by that provider, Anthropic or OpenAI respectively, under its own terms and privacy policy. Bissbilanz only sends what the assistant asks for through the tools you authorized, and stops as soon as you revoke the connection.
The iOS app can estimate a meal's calories and macros from a description or photos using Apple Intelligence. Where your device supports it, this runs entirely on your device and nothing leaves it.
If on-device estimation isn't available on your device, or can't produce a usable estimate, the app can use Apple's Private Cloud Compute instead. Your description, any photos you attached, and the foods from your own food database that match them (name, serving size and nutrition values) are then sent to Apple's servers to produce the estimate. Apple processes this data only to answer that request, does not store it, and does not make it accessible to anyone, including Apple and the developer. Voice logging on the Apple Watch always uses Private Cloud Compute, since the watch has no on-device model; it sends only what you dictated.
Estimates made with Private Cloud Compute are labeled as such in the app, and you can turn it off at any time under Settings → AI Estimation.
The mobile apps can show local notifications — for example an ongoing notification or Live Activity while a fast is running, or a reminder to log your weight, a meal, your sleep, or take a supplement. These are generated on your device; no push service is used and no notification content leaves your phone.
If you enable reminders in the web app (including when it's installed to your home screen), it uses your browser's Web Push service to deliver them, which requires storing a delivery endpoint and keys for your browser install. The reminder text is encrypted before it is sent, so the push service that relays it cannot read it.
All data is stored on a self-hosted PostgreSQL database located in Europe (Switzerland). The server is maintained by the developer. Data is transmitted over encrypted connections (HTTPS).
Bissbilanz uses the following external services:
You pick which sign-in provider to use, and only that provider is involved in your sign-in — the others receive nothing. Signing in tells the provider that you use Bissbilanz; it never gives the provider access to your food log or any other data in the app. You can link several providers to the same account, and disconnect any of them again, under Connected accounts in settings.
The web app uses a self-hosted instance of Umami to count page visits. Umami is a privacy-focused analytics tool: it sets no cookies, stores no personal identifiers, and does not track you across sites. The aggregate data (page views, browser type, country) stays on the developer's own server and is used only to understand how the app is used. The Android, Wear OS and iOS apps contain no analytics — crash reporting via Sentry is the only diagnostic data they send.
The web, Android and iOS apps tell the server which platform and app version they are, with every request. The server keeps a list of app versions and when each was last seen, not linked to you or your account, so the developer knows when an old version is no longer in use and can ask you to update. The version is also attached to error reports sent to Sentry.
Your data is kept for as long as you have an account. You can delete your account and all associated data at any time from the settings screen of the web app or the mobile apps. When you delete your account, all of your data — including uploaded photos — is permanently removed from the database. See how to delete your account for step-by-step instructions and an email fallback if you can no longer sign in.
Under the GDPR and the Swiss Data Protection Act you have the right to access, correct, export and delete your personal data. Everything you record is visible and editable in the app itself; for anything else, contact me@orellbuehler.ch.
Bissbilanz is not directed at children under the age of 13 and does not knowingly collect data from children.
If this policy changes, the updated version will be posted here with a new effective date. Since this is a small hobby project, changes will be rare.
For privacy requests, questions or bug reports, email me@orellbuehler.ch. See the support page for what to include and how long a reply takes.