Throughout the lifetime of a software system, developers continuously refactor the source code as a means of improving the quality of the code. Android apps, like traditional software systems, are not exempt from such refactoring activities. We conducted an empirical study to show the common refactoring operations in Android apps and discussed how they differ from traditional Java systems. Additionally, by contextualizing refactorings with commit messages, we identified the motivations for developers to perform these refactoring operations.