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.

The market for mobile apps is projected to generate revenues of nearly $ 190 billion by 2020. Besides native development approaches, in which developers are required to maintain a unique code base for each mobile platform they want to support, mobile cross-platform development (MCPD) approaches can be used to develop mobile apps. MCPD approaches allow building and deploying mobile apps for several mobile platforms from one single code base. The goal of this paper is to analyze the performance of MCPD approaches based on UI interactions. For this, we developed three mobile apps, one native and two developed using MCPD approaches. Using an automated test, we measured CPU usage and memory consumption of these apps when executing one selected UI interaction, that is, swiping through a virtual scrollable list. The results indicate that the CPU usage of the two apps developed using MCPD approaches is about twice as high compared to the native app, the memory consumption is even substantially higher than in the native app. This papers confirms results of previous studies and extends the body of knowledge by testing UI interactions.