Accessing Apple's HealthKit Data

This article pertains to: Legacy API (V1) Inform (v2)

Since Apple's Health data is only stored locally on my iPhone, do I need to install an app to access HealthKit data?

No. While some apps have been made to collect data from Apple HealthKit and transfer it to another app or to a server, the Validic Mobile Library is compiled into your native iOS app. HealthKit data can then be accessed via the Validic API.