9to5Mac reports this morning that Apple's long-rumored fitness and health-tracking app Healthbook is well on its way to reality. Designed to resemble Passbook, the ambitious app will apparently be able to analyze everything from activity and heart rate to blood oxygen levels, though it's still unclear what devices or third-party applications will be needed to source the data.

Everything from food intake to blood sugar

9to5 provides several detailed screenshot recreations that show what Apple is reportedly developing. According to the mocks, Healthbook will use a card interface that surfaces information according to category. Users will be able to enter metrics pertaining to their weight, food intake, activity, and sleep habits. Crucially, the app will also endeavor to analyze "bloodwork," which includes blood pressure and blood sugar levels. It is unclear how the app will source all this information in real-time — especially in the realm of blood tracking — but 9to5 speculates that the app may rely on devices like the fitness-tracking headphones it recently patented, the iWatch, or an array of third-party devices like the Jawbone Up. Additionally, the app may rely heavily on Apple's M7 motion processor, which companies like Fitbit have already started to use for dedicated tracking purposes.

Rumors surrounding Healthbook surfaced earlier this year, after Apple VP of software technologies met with the FDA in December. Apple has already hired a string of fitness experts and developers for this project, many of whom have already worked on health sensors, lending considerable credence to the rumors. 9to5Mac expects the app to be introduced with iOS 8 at this years Worldwide Developer's Conference. However, there's still the possibility that it will be delayed or scrapped altogether.