In this paper we consider the problem of energy efficient software design. We mostly focus on programming for mobile devices. A new software toolfor the analysis of energy efficiency of applications for mobile devices is proposed. The tool allows collecting and processing experimental data, which characterizes the energy efficiency of applications which are running on the platform. We compare the similar instruments. We describe thebasic functionality, method of use and the results of use on the matrix multiplication example. The analysis of the energy efficient algorithm implementations is done by using the SSE instruction set, as well as parallel programming technologies OpenMP and Cilk Plus. Additionally, we investigate the dependence of energy efficiency on the number of used threads, the quantity of cache misses and the number of transitions between the C-States of CPU. We formulate conclusionsfor the results of the analysis and present plans to further developing.