Included category icons, address book name fetching, and fixed several minor bugs. Still plenty of bugs to go e.g. when editing a transaction, the total bill gets decreased.
Persistence seems to be working in the simulator again. Next step: test on device.
Just kidding on that last commit. Persistence NOW works, including on the device (tested on my iPhone 4s).
Updated app name and icons
Lots of improvements. Added up/down arrow for latest transaction. Updated colors in some places. Updated tableview backgrounds. Several fixes to code.