Need to develop a simple app for iPhone and/or Android.  Basically, it's a calculator (for saving money towards a goal) that takes five inputs and draws a graph showing progress to date and the goal, with some simple explanation of what the inputs are.  Graph should also calculate how long it will take to reach the goal and (ideally) how changing each input by 1 unit (e.g., saving $1 more per year) would affect the goal.  Formula is known and available in an Excel spreadsheet as an example.  

Input screen can be very standard; graph should look nice (and be readable) but need not be fancy.  Will pay a bonus for multiplatform app (e.g., Java) that can be put on website as well.