Your heart already knows which meeting it was.

Telltale names it. It compares your Apple Watch heart rate in every calendar meeting with your own baseline, then tells you which meetings, people and time slots raise it, forecasts the stormy ones and finds your calmest times.

Everything is computed on your own iPhone and Apple Watch. There is no server and no account: your health and calendar data stay on your devices, and only your settings and the people, meetings and places you hide or exclude sync, through your own iCloud, which you can turn off. Telltale is in beta on TestFlight.