methods to download from Amazon S3 bucket (if we own/manage the bucket)

Some ways are mentioned at 

https://bobbyhadz.com/blog/aws-s3-download-folder

 

Cyberduck can provide a UI for Windows or Mac - "Cyberduck is a libre server and cloud storage browser for Mac and Windows with support for FTP, SFTP, WebDAV, Amazon S3, OpenStack Swift, Backblaze B2, Microsoft Azure & OneDrive, Google Drive and Dropbox."