This study explores the design requirements for mobile applications for second language learning in online/distance higher education settings. We investigate how students use technology and how they perceive that these technologies-in-practice facilitate their language learning. Structuration Theory is used for the analysis. Results show that design needs to consider that (i) students use their private mobile technologies frequently when conducting self-initiated learning tasks, (ii) students' mobile technologies-in-practice are important, and course designers should design materials and tools for such use practices, and (iii) students prefer to work on their own due to the limited time they want to devote to their learning. Consequently, in regard to the pervasive nature of mobile technology integration in society and into students' habitual use, they need various software tools on such devices to support individual learning.