Mint - This app is free and easy, and has won several awards.
Shoeboxed Receipt Tracker - How much do you spend on food? On gas? Use your phone to scan and store your receipts.
HomeBudget Lite - Keep track of your rent, tuition, groceries, etc.
Learn about managing your personal finances the fun way!
Plus, find out what portion of the tax burden you bear according to your income status.