Apple has just announced iCloud Drive, a central location for all iCloud documents, whether attached to an app sandbox or not. This is very similar to Dropbox. Files can be viewed and sync between Mac, iOS and even Windows.
An iOS document picker will enable you to access these files from within iOS apps, seamlessly.
This should allow much better project management, which spans multiple filetypes and applications. Documents appear in the Finder, with folders representing app sandbox’s as well as a freeform area to drop any other documents that users want to sync between their devices. This seems to makeup part of Apple’s new focus on “continuity”.