Over the past decade, mobile-assisted language learning technologies, such as smartphone applications, have become increasingly prominent in language learning; however, empirical research on how the use of mobile apps can influence students’ willingness to communicate (WTC) is scarce. This study assessed two mobile apps with distinct language learning approaches: Duolingo, grounded in grammar-translation and behaviourist principles, and HelloTalk, based on social constructivist theory and communicative language learning. The research examined the impact of these apps on Chinese students’ WTC in the UK. A mixed-methods approach, including a quasi-experimental design, was adopted, involving 67 International Foundation Year Chinese students from a Confucius Heritage Culture background. The participants were randomly assigned to two experimental groups (Duolingo, N = 33; HelloTalk, N = 34) and used one app for five weeks. Quantitative data were collected through pre- and post-treatment using a WTC scale and an English media usage frequency questionnaire. Qualitative data were obtained through semi-structured interviews. Results indicated that both apps enhanced WTC, with Duolingo exhibiting a slightly stronger effect. Participants displayed greater WTC with emotionally and socially connected individuals, while WTC with strangers remained lowest. Factors such as usage time, communication goals, and frequency of use influenced participants’ WTC with various groups of people.