Health Cloud is a native iPhone client for Google Health, Google’s Personal Health Record (PHR). If you don’t already have a Google Health account, you’ll probably want to sign up first.
Health Cloud is not developed by Google. Rather it uses Google Health’s publicly available API (the Objective-C GData libraries) to communicate with Google’s servers to retrieve a view of the PHR in the form of a Continuity of Care Record (CCR). The XML-based CCR is then passed through an XSL stylesheet developed by The American Academy of Family Physicians (AAFP) and displayed on your iPhone’s screen.