Review My App - mychipper.com
nbhat: Make it social. Let people compare their spending habits with other people who are in the same income category or same spending budget. 
Ask questions who is the end user? Is it a person who wants to cut down on the costs or is it person who is trying to stick to his monthly budget? If so how is the user going to achieve by using the site? 
User has to do something after seeing at the graphs. Make it easier for the user to arrive at that decision. For example food budget is higher compared to others then you can provide hints to cut down on the food budget. It may take out the simplicity of the app..
It might be good to compare how is the person doing with respect last month etc.
Notes field can be made available only if required.
Graphs are taking lot of space. Can be moved left a little bit and show a bigger recent spending list.