This article from 9 to 5 Mac discusses in detail some of the new features that could be in the new Healthbook app. And it also has some good screenshots of the app. It could possibly be released alongside the next iPhone.
Apple is said to currently be testing the Healthbook software with iOS 8, the next version of the iPhone, iPad, and iPod touch operating system. However, it is possible that the application’s launch could be pushed back to a future operating system version or cancelled entirely. If the application is tied to an Apple-built device, the debut would likely be connected to that hardware and may not be introduced alongside other iOS 8 functionality during Apple’s mid-2014 Worldwide Developer’s Conference.
With hundreds of millions of existing iPhones and many more to be sold, Apple has the unique opportunity to recreate the health and fitness tracking market by pre-installing Healthbook in a future software update. After revamping the music, smartphone, and computing worlds with the iPod, iPhone, and iPad, Apple’s next big insight could be software for improving people’s lives. Just like tablets, pocket computers, and digital music players are now part of the mainstream, Healthbook may just be able to transform healthcare and fitness management for the betterment of society.