- All the Salesforce objects whose lookup fields can be created on Cloud Document objects are supported. However, by default, the app comes with Contact object support.

- To upload files from the desired Salesforce object, you will need to create a lookup field for that object on the cloud document as described in step 3 below:

PS: View Drag, Drop & Upload Files to Amazon S3, a Salesforce AppExchange app for moving files from Salesforce to Amazon S3: https://appexchange.salesforce.com/appxListingDetail?listingId=a0N3000000B5ZPqEAN