Lifehack: Use Gmail search to look up dollar amounts on your statements.
Whatever you use to track your expenditures, categorizing purchases can be a pain, especially if you buy many types of thing from a single retailer, like Amazon.
The easiest way I’ve found to remember what a particular purchase was is to look at my credit card statement (or mint.com, etc), and search for the prices in my Gmail account. Simple, but it can really save time.