“Other” doesn't work quite like the services that we support directly. It's a way to manually keep track of a package from another service, so you can have all your shipments in one place. If you enter a date then Deliveries will count down to that delivery date for you. If you enter a web site then Deliveries will try to monitor that page and let you know when it changes. You'll also be able to tap “View details online” to open the web site and manually check the status.