Sports Tracker
- all ST activity types available
- steps displayed while tracking and recorded to workout
- possibility to display speed and average speed while tracking
- customize displayed tracking attributes while tracking
- location tracking status indicator while tracking outdoor activities
- barometer used for altitude data when available (Apple Watch 3 models)

Apple's Workout
- control music while tracking with the tracking app
- possibility to display ascent while tracking
- possibility to use imperial measuring units (set your Apple Watch region to match this )
- start a workout with count down
- possibility to use Auto Pause. Enable this from the iPhone's Watch app in Workout settings

Both apps contribute to Apple Watch Activity Rings and support Sports Tracker heart rate belt connected to Apple Watch. (Bluetooth Smart/LE)