This paper investigates smartphone use for online learning of English among Japanese university students using online surveys and semi-structured interviews. The investigation includes the most frequent smartphone activities, including language use, the main language of these activities, and the reciprocal evolutionary relationship of engaging in smartphone activities in English and the level of language skills perceived. The results show that despite the affordability of user-generated content web technologies, Japanese participants primarily accessed online language receptive skill activities. In addition, the results show the reciprocal evolutionary relationship of two complex dynamic systems, (1) use of English digital English context system and (2) English communication competency system for participants. Finally, the paper discusses how the use of English online offers a growing range of opportunities for students to engage in activities beyond the classroom, and how they are used.