it's basically

it's basically a fund tracker that you can use to calculate how much time it would take to save up for something. You set up the fund's name, it's money goal, daily accrual and the kitty which is the amount of money you start with. Piggy Banks will then calculate the estimated time at which you will reach your goal, the cool thing is that you can open Piggy Banks a week later and Piggy Banks will update your current funds according to the daily accrual you have selected.
So there you have it people, Piggy Banks is a nice little app that could be handy if you save up money for stuff. Also i suggest that you check the following screencast in order to know more about the app.