The popularity of hand-held and portable devices put the energy aware computing in evidence. The need for long time batteries surpasses the hardware manufacturer, impacting the operational system policies and software development. Power modeling of applications has been studied during the last years and can be used to estimate their total energy. In order to aid the programmer to implement energy efficient algorithms, this paper introduces an application's energy profiler, namely Valgreen, which exploits the battery's information in order to generate an architecture independent power model through a calibration process.