A major challenge for national health information systems in developing countries is their scalability and sustainability at the lowest levels where primary health care is delivered. This paper contributes to the discourse on how national health information systems can scale to the lower levels and how mobile technology is supporting the collection, handling and dissemination of data. But can mHealth go beyond the 'hype' and visions it has come to be associated with? Using an action research methodology in a long-term action research project, the usability and then scalability of mobile solutions for large scale national health information systems are studied. In this paper, initial successes and challenges with using m-Health for national public health information systems is reported and discussed.