What It Does: Slice tracks shipments and orders by pulling the tracking numbers and other details from your confirmation emails. In addition, it monitors your past purchases for price drops and recalls. There are also other features like the ability to see spending history categorized by purchase type or vendor.
What I Like: Since I live a couple hours from the nearest major shopping center, I make many purchases online. Slice notifies me when something ships, estimates its arrival date, and even lets me know when something has been delivered. (All those are dependent on the shipping company keeping the tracking data updated, of course.)
What I Dislike: The categories Slice assigns to some of my purchases do not always match the actual item that I purchased. I did download an update to the app this week, though, so some of those issues may have been fixed.