These days, most of us use Dropbox, Google Drive or Microsoft OneDrive for our cloud storage needs.
Less well known – and quietly adding to its functionality – is Amazon's Cloud Drive service, which offers three months' free trial before users must switch to a cheap- as-chips photo offering or the more substantial "Unlimited Everything", in theory allowing you to back up many laptops' and hard drives' worth of data. Earlier this week Amazon released the iOS Cloud Drive app shortly after the desktop and Android versions.
While it’s not as instantly appealing as Dropbox it’s worth it for Kindle Fire owners and Prime subscribers: there is unlimited photo storage along with the 5GB of free general storage.
https://www.amazon.co.uk/clouddrive/home