Energy efficiency is a growing area of concern for mobile developers, as good battery life is highly desired by end users of mobile devices. While many developers work to increase their app's energy efficiency during development, there is not much information available about the energy efficiency of the different app frameworks on the market. As the choice of a framework must be made before the start of development, and cannot be easily changed later on, information about these frameworks is crucial to allow developers to optimize their apps for efficiency.
In this paper, we compare the energy use of the React Native and Flutter frameworks while performing User Interface tasks to the native Android API. While we were unable to draw a conclusion about whether one of these frameworks is more or less efficient than the baseline app, we were able to identify certain UI actions that were consistently more or power-hungry than average, and found that the energy use tendencies of these actions tended to be consistent between different frameworks and devices. We also found that measuring overall energy use between separate test runs was inconsistent, and further research may be necessary to identify the best method to isolate the energy use of a single app.