In version 6.12 and later you can sync your drawings between iOS devices using iCloud Drive. You can read more about the use of iCloud in our iCloud FAQs.
(IN PROGRESS) Future: Cross-platform compatibility of Concepts drawings - to allow you to work between iOS, Windows and Android - will follow once our Android, Windows and Chrome OS platforms have caught up with the features available in iOS.
Thank you for your patience and support!
To understand the difference between syncing and backing up your drawings, read our tutorial on Backing Up Your Drawings.