AfterShip - AfterShip is the shipment tracking API for ecommerce businesses and marketplaces.
Cabubble - Taxi and minicab quotes for London, Birmingham, Manchester and throughout the UK. Book a licensed taxi or minicab online via website or mobile app.
17track - All-in-one package tracking
PostTrack.com - Universal Parcel Tracking System
couriermanager - Try couriermanager! A software solution designed especially for courier companies management. Organization, efficiency and productivity!
Instant Parcels - Package & Delivery Tracker.