The widespread growth in availability and use of smartphones and tablets has facilitated an unprecedented avalanche of new software applications with language learning and teaching capabilities. However, little has been published in terms of effective design and evaluation of language learning apps. This article reviews current research about the potential of apps for language learning and presents a taxonomy of available apps and their use for language learning. The article also presents a framework consisting of four categories for evaluating language learning apps (technology, pedagogy, user experience, and language learning) and a set of criteria within the categories. Finally, the article proposes areas for further research.