[caption id="attachment_42227" align="alignleft" width="300"] 9to5Mac's reconstructed screenshots showing how the Healthbook UI looks[/caption]

Apple is reportedly working on an mHealth app which will launch with iOS 8.

The app is currently codenamed 'Healthbook', according to 9to5Mac – echoing the name of Apple's mobile wallet app, Passbook, to which the leaked screenshots pass more than a passing resemblance – though it's unclear whether it will be made publicly available under this name.

The app will be able to track a variety of biometric data, including heart rate, blood pressure, sleep, respiratory rate, activity, and weight, according to 9to5Mac.

It's not yet clear whether this data will be sourced from the iPhone itself or a separate third- or first-party wearable device – though, given previous rumours about an Apple smartwatch, the latter seems like a good bet.

Healthbook will also feature an 'Emergency Card', which stores the user’s name, date of birth, emergency contact details, and medical information including blood type and organ donor status. It seems this information will be available for the device's lock screen, which seems sure to raise concerns about data privacy.

However, even with these early leaked details, the app represents a major leap forward for both the mHealth industry and for Apple itself, which has been criticised for failing to innovate and sufficiently differentiate the latest iterations of the iPhone.