Announcing the news on Google's Developers blog, Google Fit's Product Manager, Angana Ghosh said, "At Google I/O we announced Google Fit: an open platform for developers to more easily build fitness apps. Today we're making a preview SDK available to developers so that you can start to build."
Google has detailed that there are three sets of APIs designed to meet specific developer needs.
Sensors API provides high-level access to sensors from the device and wearables-so with one API your app can talk to sensors, whether on an Android device or a wearable. So if you're making a running app, you could register it to receive updates from a connected heart rate monitor every 5 seconds during a user's run and give immediate feedback to the runner on the display.
Recording API allows apps to register for battery-efficient, cloud-synced background collection of fitness data. For example, a running app could ask to store user's location so it can map the run later. Once it registers for these data types, collection is done by Fit in the background with no further work needed by the app.
History API allows operations on the data like read, insert and delete. When the exerciser finishes her run, the running app can query the History API for all locations during the run and show a map.
The new Google Fit framework will make use of the sensors on Android smartphones and tablets, as well as connected accessories, to collect health-related data which will be ready for apps to use. The Google Fit platform can also monitor physical activity and food intake, as well as health indicators such as heart rate and breathing. The Mountain View giant had also announced partnerships with companies such as Nike, Adidas, Runkeeper, HTC, Asus, LG and Motorola for the Google Fit platform.
"The preview SDK gives you the tools to start building your app. You'll be able to launch your app later this year when we launch the full Google Fit SDK as part of Google Play services for handsets, Android Wear and also for the web. We're excited to see what you can come up with to make fitness in a connected world better," Ghosh added.
Further, the official blog notes, "To get started, download the updated version of Google Play services containing the Google Fit APIs for Android in the Android L Developer Preview Nexus 5 and Nexus 7 system images. Use the Android SDK Manager to download the Google Play services client labeled 'Google Play services for Fit Preview'.