Currently, there is an increasing trend in the shift from the use of traditional technologies such as a desktop computer towards the use of mobile technologies such as a mobile phone. Nearly all students nowadays own a mobile device and about half of them own more than one. Therefore, students are nowadays well equipped for mobile learning. The aim of this review is to explore the use of mobile phones and/or smartphones and their apps for teaching foreign languages, specifically English, and highlight their benefits and limitations for their use in the teaching of English as a foreign language. This was done by conducting a literature search in the databases Web of Science, Scopus, and ScienceDirect, and consequently, by evaluating the findings of the relevant studies. The findings indicate that the use of mobile phones and/or smartphones and their apps generate positive effects on learning English as a foreign language, especially in the development of learners' vocabulary and their increased motivation to study. Nevertheless, more longitudinal randomized controlled studies are needed to confirm the efficacy of the use of mobile phone and smartphone apps on specific language skills and knowledge.