From the PubMed article: "A new mHealth service, Clinic Finder, was designed to provide a location-based service for any cellphone user in South Africa dialing a dedicated USSD string to find the nearest public primary health care facility. The service was funded by a European Union grant to Cell-Life to support the National Department of Health."
mFHAST Implications: Potential for use of USSD for mobile location-based services