Tracking physical activity using smart phone apps: assessing the ability of a current app and systematically collecting patient recommendations for future development. - Jennifer Murphy; T. Uttamlal; Kelly Ann Schmidtke; Ivo Vlaev; David Taylor; Mian Ahmad; S. Alsters; P. Purkayastha; Samantha Scholtz; Ramin Ramezani; A. R. Ahmed; H. Chahal; et al. (BMC Medical Informatics Decis. Mak., 2020)