Passive tracking. If you haven't heard this term yet, you will be hearing alot about it since the release of the iPhone 5s. That's because the new iPhone now has an M7 "motion coprocessor". This tiny new addition to the 5s means that it is now able to track all sorts of movements including sitting, standing, running, walking, biking, and more - all in the background without you needing to do anything but enable it once. While this may sound big brotherish to some, this is a great thing for health tech since it allows for much more accurate logging of your activities.