When an Apple Watch is paired with an iPhone, a brand new app appears. “Activity” is the app that will let you access all of your fitness activity through your phone.
So the Fitness app does exist on 8.2, it's just hidden until you connect an Apple Watch pic.twitter.com/R1BgnKYRHe
— Hamza Sood (@hamzasood) March 12, 2015
As you can see above, courtesy of Hamza Sood, visually it matches the fitness tracking elements of the Apple Watch from the screenshots that we’ve seen so far.
Further screenshots dug up by MacRumours suggest it will be very similar to Fitbit – with graphs and achievements and so on.
We’ll let you know when we have more details.