I
Yup, but it does nothing on its own, needs to be linked with other apps/devices.
It can still do some things on its own, like monitor activity levels (steps, distance traveled, flights climbed, etc.) and store emergency information. That being said, Health's true value comes in how it pools and redistributes data from many sources to create a streamlined experience between all of the user's health apps.
not on a 4s, I think