CleanTechnica's list for the top five energy efficiency apps.

Number Five – Energy-Efficient Profile on Facebook
Popular social media network Facebook is the target for an application which will, in essence, let you compete with your friends about who uses less energy.

Number Four – iamgreen’s Battery Saver
This battery saving application lets you adjust a number of power-draining settings from one single screen, instead of scrambling around the innards of your phone’s menus and settings.

Number Three – iGo Vampire Calculator
Apple latched onto the recent vampire trendiness to remind us of the old phrase “vampire energy,” which amounts to an appliance that draws power even when it’s turned off.

Number Two – greenMeter
Another application from Apple is the greenMeter, designed to tell you that you’re driving wrong. Habits like speeding, peeling out of an intersection, and slamming on the brakes at the last second use more gas than driving as slowly and steadily as possible (hint – coast toward red lights).

Number One – Light Bulb Finder
Light bulbs are the source of much noise when it comes to energy efficiency – we use them all the time, we leave the lights on, and over Christmas, we decorate our houses with them.