This is the second report on a Design-Based-Research project that aims to develop an adult literacy m-learning solution to help address persistently low adult literacy levels in Canada and across the globe. The device-agnostic solution and its key component, a mobile app, are designed to foster language and digital literacy skills needed to survive and flourish in work, school, and community contexts. This paper expands upon the previous report on design principles for developing a mobile adult literacy solution. It includes findings from literature reviews and feedback from literacy experts collected through interviews and focus groups, including participative evaluation of the app prototype. This new data provides further evidence that the three previously-identified design themes (Mobility, Learner-determined, and Context) and corresponding principles are critical to the design of a mobile adult literacy solution. Findings indicate that two Learner-determined sub-themes, overcoming emotional and motivational barriers, are also critical to a successful learning process for adult literacy learners.