This is the legacy version of the Heartbeatz Connect app created specifically for appleWatch Series2 customers. The new version of the Heartbeatz Connect app is using new features of the watch that will only work on watchOS7 and newer. Series2 owners cannot update to watchOS7.
heartbeatz legacy uses Apple Health to record your workouts you can close your rings and have your heart rate data show up on your Peloton, Garmin, Heart Zones or in front of you on any treadmill or rowing machine supporting ANT+ heart rate monitors.