Mobile devices are powered by batteries whose capacities are limited by size, so efficient management of energy becomes a very important issue in such devices. In the project 'Assistance and Remote Patient Monitoring by sensors, mobile devices and Virtual Medical Central', one of the objectives is to ensure an optimal energy management, for this purpose in this article a per-application analysis of energy consumption is presented. We used the tool 'Power Tutor', which provides information about the components of the cell phone with the highest energy consumption in each of these applications. Using these results as a reference, they got analyzed for classifying applications. Finally, some measures have been implemented in order to save energy stored in the battery.