If you're wearing a Fitbit right now there's a very good chance it's a Charge or a Charge HR on your wrist – but there's now a new Fitbit in town, and you'll want to take a serious look at it.The Fitbit Charge 2 is the first upgrade to the popular Charge range since 2013, and brings with it a couple of new features that may well tempt Fitbit fans to...