Fitbit and other devices

leebeebumble

So I looked into buying a device like the Fitbit Flex. But it seems to do pretty much the same thing that this site does, other than track your sleep. Am I missing something? And if so, what device is the best to purchase?

ctpeace

My understanding is that it also measures your steps throughout the day (and heartrate? not sure) and uses that to approximate a more accurate "calories burned" Please correct me if I'm wrong.