The Datastore API lets you effortlessly sync all of your app's structured data such as contacts, to-do items, and game state. It enables your app to sync data quickly, manage conflicting changes, and even work offline.
Before building an app using the Datastore API, you'll need to create an app on the App Console.
You also need to have an OAuth redirect URI registered on the App Console before using the API. Once you've included the script and registered your redirect URI, you can use the Datastore API in your app. Check out the tutorial and the API docs for more information on how to use the API.