File sharing between OS X server and iOS device

I was trying to read into the differences between OS X server 3 and 4 (Yosemite) when I stumbled upon this rather interesting page.

OS X Server File Sharing service lets users store and share folders and files on the server. Users can access file shares from Mac and Windows computers and from iOS devices, with no special software

They specifically say that it should be possible to access file shares from iOS devices without third party software like e.g. Transmit. I can however not for my life find anything, anywhere about how this is actually supposed to work or how one would configure it.

Spontaneously it sounds like it would be handled by the new storage provider API in iOS 8, but as far as I can see, only iCloud drive is included in the system.

Does anyone know anything about this?

Looking at https://jamfnation.jamfsoftware.com/discussion.html?id=16976 the key is to configure a 'mac os x server' account, and then enable iCloud Files. That way you can access files on the server just like iCloud files.

Only downside I've found so far, you need to enable iCloud files too, you can't just use file sharing of OS X Server.

OS X Server allows you to set up file share points using the WebDAV protocol. This in turn allows iOS apps that support WebDAV access the files on the share point. Since iOS doesn't allow the user to browse the device file system, there is no way to upload or download arbitrary files just on the device.

However, within an app that supports WebDAV, you can download and upload files. Three examples are the iWork apps for iOS, which include Pages, Keynote and Numbers. WebDAV Navigator is another example.