With iOS 8, Apple totally transformed iCloud to a fully fledged storage solution. Apps could already use iCloud to store and share data across devices of the same user, Now you can even store your own files in a folder that Sync’s across the devices. This is an app called the iCloud Drive, however, the main problem here is that this app doesn’t come on the iPhone
Upgrading the iPhone or iPad to iCloud drive:
This the first step to getting you started, and you might probably have done it already while updating the iPad or iPhone software, To do this on your iPhone or iPad, go to Settings > iCloud > iCloud Drive and look for an option that says Upgrade to iCloud Drive.
For a Mac you should be going to System Preferences > iCloud > iCloud Drive, On a Windows PC, you should first download the iCloud manager, sign in with your iCloud account and you should be prompted to upgrade to the iCloud drive.
iCloud allows for the upload of any file type as long as the iCloud storage limit is not reached, you can even create folders to better organize the files that you upload.
Access the files on an iPhone or iPad:
Unfortunately, Apple hasn’t included the iCloud drive file manager on the iOS devices, although the other apps have access to the folders, there’s no way to access the folder on iOS without a third party app. Although Apple’s own apps provide access to the iCloud storage, they do not provide access to the filesystem, so it is recommended to use a third party file manager like Document 5.
After downloading the app, you should be able to access the iCloud storage by tapping the iCloud tab and selecting iCloud drive option. This should display all the files and folders, tap on the file and the app will display it if the format is supported. You can choose the share option to import the file and open it in another app.
iCloud Drive on OS X Yosemite:
iCloud drive feature is built into the OSX Yosemite, you could directly fire up finder windows and select iCloud drive from the left sidebar. Here you can directly drag and drop to create files and Mac will update you about the sync progress below the file name. It should be noted that empty folders and files don’t seem to be syncing and it might not be displayed on the other Mac’s.
iCloud Drive on Windows:
Since iOS 5, Apple has provided Windows software that would let the backup of pictures from an iOS device and also makes some changes to various things in iCloud, provided they run Windows 7 or above. This same software has provided the capability to make use of iCloud drive feature right from the Windows Explorer.
Once you download iCloud for Windows, after the sign in and installation, the installer would have created an iCloud folder in the user directory. Here you can drag and drop files or simply copy and paste them, and they will be updated across all the devices.