Here at HuffPost we're all about the Third Metric. But it sounds like the next iPhone will be looking to out-do us -- at least in number -- by adding fourth, fifth and sixth metric tracking sensors to its hardware. And now researchers in the US are working on yet more sensors for future devices.
The latest pre-release version of iOS 8 now comes with step-counting and caffeine tracking all through Apple's new Health app.
Available on the iPhone 5s, the step-counter uses the iPhone's advanced M7 Co-Processor which has been specifically built to tracking movement without using the same kind of battery-draining power that the main processor normally requires.
With iOS 8 just a few months away medical professionals are already looking 6-12 months ahead with the next major breakthrough arriving in the form of stress-testing.
READ MORE: Apple Unveils iOS 8 And Mac OS X Yosemite
Meanwhile researchers at Intermountain Healthcare in Murray, Utah have announced that by using little more than a simple tube, some software and some saliva, a smartphone woill one day be able to accurately measure your stress levels.
Speaking at a conference in Chicago, lead researcher Dr. Joel Ehrenkranz explained the significance of smarter, more advanced portable devices.
"Parts of the United States and the rest of the world that lack facilities to measure cortisol will now be able to perform this essential diagnostic test, also, measuring salivary cortisol with this technology will provide a way for individuals to monitor their personal biometric stress levels easily and inexpensively.”
The device costs little more than £3 and would save huge amounts compared to the $50 that NY Daily News reports it would cost to have the test done in a hospital.