This year it seems that we we have the great revolution of device wearables as they say those of Anglo-Saxon language either devices to take jobs. It is something that we have seen in CES 2014 and seems Google work has already been hands to facilitate their interaction in Android.
Many of the presented devices have been bracelets with a series of sensors working mode of quantification of activity or exercise and that Google could do that they popularize further thanks to Bluetooth 4.0 and work at the API level that is doing.
Details of the new API Google fitness
Android 4.4 brought features that will improve monitoring of sporting activity and external sensors. A new API allows that Google read and write data on the basis of the information from these sensors.
At the moment it is not known if an API as such integrated in Android will finally reach or we will end up forming part of Google Play Services.