I can and see folders for Keynot, Numbers and the other Apple Apps. These folders did not appear initially after DP3 install.
On DP2 I tried copying all my docs there just for fun and it worked fairly well.
ls -al ~/Library/Mobile\ Documents | head -n 2
Well you can always check if it is actually read only with the terminal command
Code:ls -al ~/Library/Mobile\ Documents | head -n 2
should be drwxr-xr-x
Aside from checking that I'd just recommend trying these things:
1) Enable and disable iCloud Drive in system preferences
2) Sign out of iCloud in system preferences and sign back in
3) Restart your computer
I also can't use iCloud Drive for some reason... (DP3)
I'm able to store files there, but i'm still missing the iCloud Drive app on iOS and also a webapp on iCloud.com to access the stored files like in Dropbox.
I don't think there will be an app on iOS. Instead each individual app will be able to save documents to the iCloud drive. In a particular app that supports iCloud drive will have a browser like app to save or load files.
As Apple write on their website uploading and accessing files through the Finder or Windows Explorer will be possible.
Did you try all three things I posted above?
Nope. This is OS X, so I want it out of the box. 😀