WWDC
Similar to Dropbox, iCloud Drive lets you store and access all of your files from any computer.
iCloud Drive also boasts a relatively similar interface to Dropbox and Google Drive. You can sort and organize your files as needed. Each app - be that Keynote, Numbers, or Pages - has its own folder.
Once you sync up your files, you can access them from other Mac computers, as well as iOS devices. Bonus: iCloud Drive will even work for Windows.