M-learning has established itself as a popular and effective educational method, leveraging the universality of mobile devices. This approach is particularly valuable for continuous training of teachers in rural areas of low- and middle-income countries. This paper presents a systematic review of the literature on m-learning from the perspective of Human-Computer Interaction for Development (HCI4D), focusing on these regions. Databases including Science Direct, ACM, and Google Scholar were searched, ultimately selecting 52 articles published between 2014 and 2024 through specific inclusion and exclusion criteria. The PRISMA framework guided the analysis, uncovering various gaps in m-learning for longlife learning in rural areas. The review identified important gaps and opportunities at the intersection of HCI4D and m-learning in relation to themes of interest, geographical coverage, preferred methodologies and technological focus.