Great project! Using mobile is a great way to get to the most possible people, particularly BOP users in Sub-Saharan Africa. Finding a cheap way to allow users to interact with audio material will really help to promote literacy, wherever they happen to be! And if a complimentary wraparound service can be created to continue this engagement with quizzes and articles, all the better!
What a fantastic idea- literacy really is the source of expanding one's knowledge and resilience- and feature phones are the primary means by which young and old alike across Sub-Saharan Africa engage with. So by combing the two you are giving a platform for real growth!