The Google Fit SDK is an open ecosystem made up of Android device APIs & a RESTful API for all platforms to access. The APIs access wearable device sensors to sync Google Fit data with a single repository, the Google Fit Store, where they can interface data with 3rd party applications. The SDK consists of the fitness store, a sensor framework, permission and user controls, and the Google Fit APIs.
As with all app platforms, the value of Connect IQ is built around the quality and quantity of apps in the system from third-party app developers. This post, from the creator of the SkyWatch app, looks at the experience of developing a wearable app using the Connect IQ platform.