I know you love a 20-25 digit tracking number that isn’t separated by spaces. I know you love making me type all those numbers into a crappy and confusing website. It would be really awesome if you would just put a QR code on the receipt that my phone could automatically detect and track. It would be sweet if the app even enabled push notifications so I got a text when the package was delivered.
Best,
Dustin
ps I wish I were a good enough programmer that I could whip up an optical character recognition program tonight that just reads the numbers directly and without a QR code. 
Delivery Status for iPhone will push a notification when your package is delivered. It will also live on your Mac’s Dashboard and Growl at you.
You still get to type in a high-tech tracking number though!