Google Fit's open APIs allow any connected apps and devices to seamlessly share data, all of which gets sucked up by Google Fit. Fit is supposed to make it easier for you to analyse data from all your various health-tracking apps.
The idea is that we've reached a point where annual doctors' visits have become largely obsolete. While there are obvious exceptions, we are perfectly capable of measuring all our vitals. And Google wants to give us the tools to do it. As BussinessWeek wrote in a profile of Sundar Pichai, the chief of Google's Android division:
Pichai says it's "crazy" that people visit their doctors, at most, once a year to have their heart rate and blood pressure measured. "You obviously need to be able to measure these things so many more times and then apply more intelligence to it," he says.
There's already a whole slew of third-party developers on board with Google Fit, one of the more notable being Nike, which will allow all the data pouring into Google Fit's API to integrate with Nike Fuel, too.
Developers will be getting Google Fit's SDK in just a few weeks, but no word on availability for the health-concious masses.