Now, the advent of wearable devices bristling with sophisticated biotracking sensors is stirring concern in the medical community about misdiagnoses that could have serious consequences for consumers. Some are asking whether Apple and Google should do more to police their fast-growing app marketplaces. “Most of the health apps out there are built by people with zero medical experience,” said Paris Wallace, chief executive officer of Ovuline, a popular fertility app. Worse, many developers don’t have the resources for legal counsel, Wallace said, and are more likely to make false claims to patients without seeking FDA clearance.