Your Health data stays yours

Your drinking history is personal. KATER ZERRO works with Apple Health only for the data you explicitly allow, so you decide which information is available to the app.

Alcohol consumption is the essential permission. Sleep, resting heart rate, heart-rate variability and other recovery signals are optional, and only matter if you want to explore your own day-after patterns.

There is no KATER ZERRO account, no advertising tracker and no app backend collecting your history. Your data remains in Apple Health on your iPhone, or in iCloud when that is how you have configured Apple Health.

Permissions can be changed at any time in the Health app. If you prefer to log drinks without sharing additional health data, the logger and trends still work as a private record of your own.