I was a little confused by this as well because the package was updated to a new version then a few hours later unable download - so im guessing everyone who ever has usps has to email him for the upgrade ??
The developer has notified that he is unable to continue developing and supporting this for new users and new versions of concrete5. It is effectively withdrawn from the marketplace and no longer available for download. The developer will provide base support for existing users, but does not want new users, even unsupported.