Hey! We created Caffeine because existing solutions either didn't work with Apple Health or didn't look like something we wanted to use ourselves.
We wanted to get this out there as early as possible, so the functionality is pretty limited for now: you can add beverages to your daily caffeine intake and Caffeine will add them to Apple Health. An extension for Apple Watch and some other features are coming soon and we're definitely listening if you're missing something.
If there are any questions, I'm happy to help ☺️
Iris