Apple Watch
Running with your watch, without your phone
Open Why Not on your phone before you head out, so the watch has today's workout. Then you can leave the phone at home: the watch runs the workout and records the run on its own, with its route on an Apple Watch with GPS, and its heart rate and splits.
The watch keeps the run and saves it to Apple Health. When the phone is in reach again and Why Not opens, the run goes across and lands on Home and in Activities.
On a rest day or a strength day, FREE RUN works the same way.