Mobile touchscreen applications present new opportunities for children's language learning. This systematic review synthesizes the evidence on the impact of features of mobile applications on children's language learning. Experimental studies published from 2010 onwards with children aged 3 to 11 years old were included. Of the 1,081 studies screened, 11 studies were identified, which examined four features of mobile touchscreen applications: inbuilt narration, real-time conversation prompts, augmented reality (AR), and hotspots. Inbuilt narration had a positive impact on story comprehension and word learning compared to reading alone but not shared reading with an adult. Real-time conversation prompts improved the quality and quantity of adult-child talk, and AR supported language learning ostensibly via increased motivation. No evidence was found for an impact of text-relevant hotspots. Limitations of the existing literature are discussed, and a strong case is made for further research in the area, particularly that which builds on learning theory and existing qualitative research.