Share task list between people using iCloud

Question

I'd like to create an iOS app for shopping lists (yeah, one more), allowing synchronization between 2 (or more) iCloud users (like what Apple does with shared calendars).

Any idea how I should structure my data to accomplish that ? Can I do that with the tools iCloud offers at the moment in iOS 8?

EDIT: I'm especially interested in the sharing part of the process: how to "invite" other users (as in the Calendar app to "Add Person" for a shared calendar), or maybe include Family members (as declared in iTunes) in the app.

Thanks

Answer 1

iCloud app data is sandboxed and not accessible by other users https://developer.apple.com/library/ios/documentation/General/Conceptual/iCloudDesignGuide/Chapters/iCloudFundametals.html

In CloudKit there is a private and a public database. when you write to the public database, then that data could be read by others. https://developer.apple.com/icloud/documentation/cloudkit-storage/

Cloud Kit may be your best option