Link your accounts, bills, and credit cards to Mint (free), and this app will do all the tough number crunching for you. It offers tools for tracking your investments, as well as categorizing purchases to help you easily see and analyze trends in spending. Mint also offers a free credit score service, helping you become more informed and educated on your finances. Bonus: Mint is colorful and geometric, making this app as pleasing to your eye as it is pleasing to your bank account.
Available for iOS and Android