Dropbox

Access your documents, photos, and videos from the cloud with Dropbox.  Listen to your audio files with a built-in audio player.  A recommended alternative to Dropbox would be Google Drive.

https://itunes.apple.com/us/app/dropbox/id327630330?mt=8

Google Drive

Create or access existing documents and spreadsheets with Google Drive.  Your files are stored in the cloud and can be easily shared with others.  Pictures and videos from your iPad can also be saved to Google Drive.

https://itunes.apple.com/us/app/google-drive/id507874739?mt=8