In South Africa, many young children from poor social and economic backgrounds are cared for at home by parents or guardians who are themselves illiterate. This leads to poor educational outcomes later in life. Yet there are many privileged teenagers with access to mobile technologies who spend a greater portion of their spare time interacting on ubiquitous social media platforms. This presents an opportunity whereby the poor educational outcomes referred to previously could be addressed by applying a technology solution providing social media-based homework support by privileged teenagers to underprivileged younger children. However, most applications designed for use by children are designed by adults, with little understanding of the user requirements of the target end users. This research explores the following question: How can a cross-age tutoring system be designed for implementation on a social networking platform to support numeracy and literacy skill acquisition? The main contribution of this research was the definition of the Cooperative design by Children for Children (CD2C) Design Framework, a blueprint of how a cross-age tutoring system could be co-designed by children of different age groups and life circumstances. The CD2C Design Framework was derived as an abstraction of the second contribution of this research, the TitanTutor, an artifact designed using co-operative inquiry method and the Design Science Research approach. The third novelty of this research was contribution to Design Science Research theory, with the addition of new theory that states that cooperative design by children from different age groups and life circumstances is tempered by socio-environmental context and power relations between the co-design partners. This work provided important contributions to researchers in the areas of Cooperative Inquiry (CI), Human Computer Interaction (HCI), and Design Science Research (DSR). Future researchers could extend the CD2C Design Framework to make it even more abstract, thereby making it universally applicable to any co-design scenario. / Computing / Ph. D. (Information Systems)