GO GREEN AND SAVE MONEY!
This calculator shows the savings to be made when replacing normal incandescent bulbs with energy saving bulbs, whether replacing with CFL or LED.
This app will allow replacing any number of bulbs of a particular size, or sizes, and will give the cost savings to be made over 4 hours use per day over a year in time. It will also allow the user to input the names of rooms and the wattages of any number of bulbs per room, to correspond with the list.
Further ways to reduce your energy consumption can be found at http://www.eco-bulbz.com/
Reduction of energy use will not only affect the savings you can make, but also be of benefit to the planet by the reduction of the amount of energy used.