  Building energy efficient software is an increasingly important task for
mobile developers. However, a cumulative body of knowledge of techniques that
support this goal does not exist. We conduct a systematic literature review to
gather information on existing techniques that allow developers to increase
energy efficiency in mobile apps. Based on a synthesis of the 91 included
primary studies, we propose a taxonomy of techniques for improving the energy
efficiency in mobile apps. The taxonomy includes seven main categories of
techniques and serves as a collection of available methods for developers and
as a reference guide for software testers when performing energy efficiency
testing by the means of benchmark tests.
