This study examined the role and impact of mobile tools and AR as collaborative educational resources with respect to their affordances of facilitating college EFL academic writing. These affordances are proposed for their multimedia learning effects on the development of EFL learners' writing achievement. In order to investigate the role and impact of mobile and AR affordances, the study explored the learners' needs assessment including personas, learning objectives and content, learning strategies and learning context so that the design of learning activities could be formulated under the theory of change. Furthermore, it discusses the differences between the impact of mobile and AR affordances under Haye's writing model, with the living-system approach and DMC as conceptual framework. The findings of this study revealed that the appropriate use of ICT multimedia tools like mobile media and AR play a positive role in improvement of learners' English writing quality. Also, L2 learners' writing engagement and motivation are expected to develop significantly with help from either mobile media or AR. Although ethically speaking this evidence was not conclusive as it was limited by literature analysis without experimental data, it could be predicted that mobile tools are appropriate for EFL collaborative academic writing, given their main affordances of availability, connectivity and accessibility, learners can enjoy circulating assistance at each phase of writing. Meanwhile, AR would be recommended in the same study field for its strong potential and unparalleled affordances of authenticity, motivation and multimediality. Future studies are hoping to explore more comprehensive affordances supported by exact experiments and reliable data.