Health Tracking additions

Won't this drain a lot of battery?

Not really - once a second it would have an impact for sure, but adding maybe 1ms worth of extra power draw every 60 seconds should be pretty minor.

Could the firmware not manage the reset at midnight as per current locale setting ?

It could do, but what if you're doing exercise over midnight? The app would have to be aware that the step count will reset to 0 mid-exercise. Although I guess in that case it should just be using the step event and counting itself...

I'm thinking that the best option for steps is to have a health library provided by the health application that provides the step count for the day, and the goal, and also has some functionality for grabbing historical data too