Despite an improving interest in mobile-assisted language learning in recent years, little is known about second language (L2) learners' use of and attitudes to smartphone apps in learning English. This study explores L2 learners' purposes for and attitudes toward using Smartphone English Language Learning Apps (SELLA) in the Vietnamese context. A sample of 123 Vietnamese EFL students from different universities in Southern Vietnam was invited to fill out a 5-point Likert-scale questionnaire. Data were projected into SPSS 25 for analysis. Results indicated that the participants generally used SELLA to practice and improve all language systems and skills. Also, the students generally showed their positive attitudes toward SELLA. The findings suggest implications for using smartphone apps in English language learning in Vietnam.