Fitbit Charge HR tracks continuous heart rate, all-day activity stats and sleep. It also has a phone pairing function that allows it to display the caller ID should you get a call on your paired Android or iPhone.
It also supports:
PurePulse Heart Rate
Get continuous, automatic, wrist-based heart rate & simplified heart rate zones.
Get real-time run stats & review routes, splits and workout summaries on the app.
Caller ID + Watch
See daily stats & time of day, and get call notifications with compatible devices.
Long Battery Life
Lasts longer than competing trackers with a battery life up to 5 days.
Automatically recognizes select activities and records it in the exercise section of the Fitbit app.
Sync stats wirelessly & automatically to leading smartphones and computers.
Workouts + All-Day Activity
Track workouts, heart rate, distance, calories burned, floors climbed, active minutes & steps.
Auto Sleep Tracking & Silent Alarms
Monitor your sleep automatically & set a silent alarm.