With iOS 8 came iCloud Drive; and now, there's an app for that. iCloud Drive is, simply put, Apple's Dropbox. When you're logged into iCloud, you can easily save files to the drive, which are then accessible across all iOS devices and work in conjunction with OS X and Windows. With iOS 9, Apple has added an iCloud Drive app that makes it easy to view, edit, and manage the documents saved to your drive. The app is automatically included in the new update; however, the option to display the iCloud Drive app is hidden in your Settings.
Open Settings and Tap iCloud. Open iCloud Drive.
Turn on Show on Home Screen, and the iCloud Drive app will appear among your other applications.