I also like the trackmyshipments app. They just changed from a lite to a paid to a free + upgrades thing. I just tested out the new one and it seems to work fine, and I paid for the push messages (though I don't really think I needed to... it had email). I'm a sucker, I guess.
Anyway, when you get an email from Amazon or ebay or any email that includes a tracking number for a package, you simply forward that email to the address they give you and it looks at your email account and reads for shipping info and loads that into its system. It automatically adds the shipment and updates you on the status. (Through the website you can adjust settings for what you want to be notified about: statues changes, deliveries, etc.)
Inside the app was kind of ugly before, but they released-yesterday version has a tad more shine to itbut who cares, it works! I'd tried other apps that make you copy/paste shipping info and then tracks packages in a similar way, and some of those worked very well. I much prefer this method. It's just a simple email forward and forget about it!
(full disclosure: I had a couple of instances where it didn't read tracking data from emails. This turned out to be, I think, shipper error. From memory, both cases had UPS tracking numbers separated by dashes or spaces rather than the whole number. A follow-up forward with a quick edit solved it. So their system isn't foolproof, it works most of the time.)
I noticed a lot of negative reviews on iTunes and don't really get it. I think it works great. Hope that wasn't too long. So one vote for:
TrackMyShipments +
Also, it's now 7.99, but I really like 1Password Pro. If you don't use 1Password's desktop edition (Mac only) then I don't know if the price tag would be worth itthough it does rule, especially the bookmarklet that takes you to a specific entry in the app for a particular login when in Safari to copy info for loginsand if you're not using 1Password why aren't you!?
Hope that's helpful, and understandable. It's really early.