Quantifying and long-term monitoring the energy consumption of software in end-user computers is a complex task. It brings multiple technical and sociological challenges. End users need to visualize their energy consumption and get a per-software feedback about their energy impact to adapt their software usage towards a greener approach. In this paper, we present our monitoring and feedback architecture: Demeter. Our distributed approach monitors energy consumption per application on runtime, provides end users with immediate feedback through a graphical user interface, and delayed feedback through an analysis email notification. We illustrate our approach with a two-week study of software usage of three different user profiles in a corporate environment.