Systems and methods for the of use information from application programming interfaces on wearable devices in third party applications are provided. A system comprising a user device, data storage, an application programming interface and an application is provided. In this system, there is a user device that includes a health monitor. The health monitor includes sensors and associated software that enable it to obtain health information about the wearer of the user device. In this system, there is data storage on the user device that stores the health information as user health data. In this system, there is an application programming interface on the user device that enables the health monitor to share the user health data with other applications executing on the user device.