The news comes after The New York Times discovered that high-level Apple executives met with directors of the US Food and Drug Administration (FDA) to talk about mobile medical apps in January.
According to 9to5Mac, The Healthbook app will be able to track steps taken, calories burned and distance travelled, in addition to keeping a tally on your weight loss (or gain, for that matter). Not dissimilar from the Samsung Galaxy S4's S Health app, then.
But Healthbook reportedly goes further still, being able to track your blood pressure, heart rate and hydration levels, in addition to glucose levels, with the right accessories. An iWatch or other wearable could potentially tick that box; the readily available iBGStar, which plugs into the iPhone or iPad's dock connector, already measures blood glucose levels.
The Healthbook app's interface itself is reportedly based on Apple's existing Passbook app and will offer extra functionality including medication reminders.
We expect that users will need to pair the app up with an iWatch to collect the more complex data, and 9to5Mac's sources told the site that the iWatch is well into development.
If the speculation turns out to be true then Apple won't be the first company to release hardware or software centred around health tracking, so it will need to offer richer data or more seamless integration into everyday life to succeed.