Longaccess uses AWS Glacier too (a combination of S3 and Glacier, actually). The added value comes from a couple of features, like:

- making the use of Glacier friendlier to the average user

- providing a well defined way of accessing the data (retrieval, decryption, etc.). This is very useful if, for example, you want the files to be retrieved by your children in a couple of decades

- making a commitment to take care of the data for decades: if Amazon decides in 10 years that they are no longer interested in being in this business, we will move the data to an alternative provider, but nothing will change for our users.

Disclaimer: I'm the founder of Longaccess.