True, that is indeed what Health Kit is for. I was merely sharing my experience with the iOS build-in Health app, which I believe is buggy. Entered hours of sleep manually this morning: from 01.00 to 08.00 gives me 6h44m of sleep(?). There are bugs like this one throughout the app. Plus I don't understand why it can't do the simplest math: entering your height & weight doesn't give me my BMI, an easy calculation.Again, the app, not the Kit.