Abstract The computer and online technology world continues to evolve rapidly, with vast improvements in new devices such as smartphones. With these changes, scholarly attention to the impact of mobile technology on literacy development, especially self-based language learning and practice, has also increased. This “virtual space” can create a meaningful motivation for learning and may offer a small yet pertinent support to literacy practices in transnational migrant contexts. The research questions that guided this study were (1) what are the unique mobile literacy practices that Korean teenagers in the US engage in? And (2) how do Korean teenagers in the US reflect upon their local integration and identities through mobile devices? This study draws from new literacies and Norton’s theory of investment and identity. The primary data are semi-structured interviews collected over a three-month period and were analyzed using constant comparison. Findings show that immigrant teenagers’ continued language practices involve their preferable transnational affiliation on social media. Furthermore, findings suggest that participants’ intention to use mobile phones sometimes masks their insecure personality to help them assimilate into a community to which they wish to belong. A better understanding of mobile literacy practices in transnational migrant contexts offers insights for language teachers and educators in the US.