The client application of Samsung Cloud is preinstalled on phones and tablets, released later the second half of 2016 (more precisely, after the release of Samsung Galaxy Note 7). Registration of an account on the service is possible only through it, apparently, to screen out strangers.
The amount of free storage is 15 GB. Additional 50 GB cost $ 0.99 per month, and 200 GB - $ 2.99.