I just found out I'm anemic and it's because I benge eat so I want to count my calories so I'll stop doing that!
I think it counts calories burned while working out.
Yes, burnt calories are shown during the workout and after you've completed it you can also check them up visiting the "History": selecting a workout some details will show along with "burnt calories". But they are "esteemed", they're not much reliable... I guess they depend mainly on how long the workout lasted.
You might have to "tick" the option "Show calories" though, in your settings.