Google has released a preview software development kit (SDK) for Google Fit, the platform the company will launch later this year to help Android users aggregate data from fitness apps and devices. The preview launch gives some hints about what the final SDK will look like when it launches later this year.
In a blog post, Google explained that the preview SDK will contain three different APIs. The first, a Sensor API, will allow a developer's app to talk to sensors either embedded in an Android phone or in a connected 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," Google Fit product manager Angana Ghosh writes.
The other two APIs are a Recording API, which allows an app to work in the background of the phone to detect other kinds of data, like location, continuously without using too much battery, and a History API, which allows the app to access similar data after the fact. The History API will be able to pull batch data from pre-existing apps on a user's phone.
"Google Fit provides a single set of APIs for apps and device manufacturers to store and access activity data from fitness apps and sensors on Android and other devices (like wearables, heart rate monitors or connected scales)," Ghosh wrote. "This means that with the user’s permission, you can get access to the user’s fitness history -- enabling you to provide more interesting features in your app like personalized coaching, better insights, fitness recommendations and more."
The preview SDK is intended to let developers get started, so that when Google Fit launches later in the year there will be already available apps using it. According to TechCrunch, certain previously promised features aren't yet included in this release: The Recording API's background data collection will eventually be cloud-synced, and Google has promised a REST API that allows for web development (in addition to mobile) and specific APIs for Android Wear.
Google Fit has already partnered with various companies that offer digital health apps and devices including LG, RunKeeper, Polar, Basis, Motorola, Asus, Noom, Withings, Adidas, and — somewhat surprisingly — even Nike, which has had a longtime relationship with Apple and only very recently launched an Android app.
Neither Google Fit nor Apple's Health app have been released yet, but both companies have previewed the products, Google with its developer preview, and Apple in the iOS 8 beta, which has updated a few times with new tracking features for the company's built-in health-tracking app, simply called Health. Samsung, meanwhile, has yet to make a move beyond announcing SAMI (Samsung Architecture Multimodal Interactions), its own aggregator platform.
