Today we’re introducing two new ways for apps to build even richer integrations with Drive: app data folders and custom properties.
In order to run smoothly, your app may depend on data it stores in Drive. But occasionally, users may accidentally move or delete the very file or folder your app needs to function. The app data folder is a special folder in Drive that can only be accessed by your app. The app folder’s content is hidden from the user and from other apps, making it ideal for storing configuration files, app state data, or any other files that the user should not modify.
Although users cannot see individual files in the app data folder, they are able to see how much app data your app is using and clear that data in the Manage Apps dialog.
Apps can also now add custom properties to any Drive file. The new properties collection gives your app the power to create searchable fields that are private to your app or shared across apps. For example, a classroom app could keep track of the grade for a document or a project management app could keep track of the current status of a document going through a review process.
To learn more check out the technical documentation for both app data folders and custom properties, and if you have questions don’t hesitate to post on StackOverflow.