Mobile-assisted language learning has expanded beyond relatively humble beginnings of replicating computer-based activities assigned in formal language learning contexts, and it now often consists of a complex mix of formal and informal learning activities that take place at different times and places throughout learners' daily lives. Decisions about what tools to use are often driven by the costs, choice of hardware, and the knowledge of what tools actually exist, and how these tools are then used will depend on learners' skills, motivation, as well as their short- and long-term goals. Language learning no longer needs to be an activity that is separated from learners' daily lifestyles, but can be an integral part of their lives in the long term. The complexities involved in understanding each individual learner's own ecological context and how these ecologies shift over time will be discussed with an eye on optimising learning opportunities for learners that will keep them engaged in learning throughout their lives.