Support and Frequently Asked Questions

Where do you store data ?

Data is stored in the Apple Health application and its underlying HealthKit database. We do not store data outside your phone.

I accidentally created an entry. How do I remove it ?

Navigate to the History tap and left swipe on the entry. This will delete it from the Apple Health database.

I forgot to put an entry in earlier in the day. Can I retrospectively add it ?

Right now we do not have a feature to enter historic data. However you can do this manually through the Caffeine section in the Health app via the Add Data link.

Where do the caffeine estimates come from ?

We have used a variety of sources for finding caffeine levels, including the Starbucks menu guidelines. Where there is a range, we have picked a mid-point.

How do you calculate current and projected caffeine

We work with a half life of a caffeine dose of around five and a half hours, which generally applies for an adult non-smoker who is not pregnant. While weight etc is a factor, it is not too significant although individuals obviously vary. Note that caffeine takes a long time to fully clear.

How should I read the sizes ?

For coffee and tea beverages (filter, French press etc) the sizes align with Starbucks sizes (Short, Tall, Venti, Grande). For Cola, 335ml is a typical can size. Subsequent sizes are increasing typical bottle sizes.

Why is the Tea caffeine content so low ?

There are a lot of teas and they vary. We used a number for 'generic black brewed tea'.