Fuel Band, JawBone Up or FitbitThe iPhone 5s can be a handy tool and fitness bands like the Nike Fuel Band, Jawbone Up and Fitbit can make great accessories.
All of these fitness bands connect to the iPhone 5s in some fashion to sync data to a companion app. The Nike Fuel Band uses Bluetooth, the Jawbone Up plugs in to a headphone jack and the Fitbit syncs to a computer and then to the iPhone app.