Xindus's answer
FedEx - FedEx app features the creation of a large number of national and international shipping labels so you can keep a record of the status of the online package right at your fingertips.
Delhivery - Delhivery is an E-commerce logistics solution.
TrackChecker Mobile - TrackChecker Mobile app features tracking of parcels and online orders, so users don’t have to worry about losing a package by tracking the parcel right on their mobile phone screen.
PDFCrowd - Pdfcrowd is a Web/HTML to PDF online service. Convert HTML to PDF online in the browser or in your PHP, Python, Ruby, .NET, Java apps via the REST API.
DocRaptor - As the only API powered by the Prince HTML-to-PDF engine, DocRaptor provides the best support for complex PDFs with powerful support for headers, page breaks, page numbers, flexbox, watermarks, accessible PDFs, and much more
ShipERP - Dedicated to increasing supply chain efficiencies for Fortune 500 companies and other enterprises looking to transform their order-to-cash process via shipment optimization.