* This repository will be continously maintained and updated. If you have any suggestion (e.g., reporting errors, updating some items, or proposing new relevant publications), please let us know through the github issue system (GO).
Testing Android apps is essential for app user, app developer and market maintainer communities alike. Given the widespread adoption of Android and the specificities of its development model, the literature has proposed various testing approaches for ensuring that not only functional requirements but also non-functional requirements are satisfied. In this paper, we aim at providing a clear overview on the state-of-the-art works around the topic of Android app testing, in an attempt to highlight the main trends, pinpoint the main methodologies applied, and enumerate the challenges faced by the Android testing approaches as well as the directions where community effort is still needed. To this end, we conduct a Systematic Literature Review (SLR) during which we eventually identified \paperNo{} relevant research papers published in leading conferences and journals until 2016. Our thorough examination on the relevant literature has led to several findings and highlighted the challenges that Android testing researchers should strive to address in the future. After that, we further propose a few concrete research directions where testing approaches are needed to solve recurrent issues in app updates, continuous increase of app sizes, as well as the Android ecosystem fragmentation.