In September 2015, the United Nations ratified 17 Sustainable Development Goals (SDGs), including a central goal to improve the quality of learning, and attain universal literacy. As part of this effort, the UN and other funding agencies see technology as a major enabling tool for achievement of the SDGs. However, little evidence exists concerning major claims about the success of particular interventions, especially in developing countries. An additional barrier to achieving the SDGs for education is a better understanding of how learning occurs for promoting successful transfer of reading skills in linguistically diverse settings. This research investigates the impact of a computer-based early grade reading intervention for improving literacy outcomes in rural South Africa. Results show that learners in intervention schools performed significantly better on mother tongue reading fluency measures, as well as comprehension. Further, this study identified a pair of values by which mother tongue decoding skills significantly improved the ability to predict transfer of skills to English. The findings indicate that teaching literacy through guided and contextualized digital material can support development of early reading skills. However, more research is needed to enhance sustainability of the treatment effect over time. The results further demonstrate the importance of establishing baseline reading skills in a mother tongue language for improving transfer of literacy skills to English.