The percent of adolescents meeting physical activity (PA) guidelines is low. Mobile technologies may provide opportunities for PA promotion. The purpose of this study was to examine the perceptions of smartphones in low socioeconomic status youth, with the intention of informing the design and integration of smartphone PA gamebased applications (SPAGAs) to promote PA for at-risk adolescents. This exploratory qualitative study targeted an afterschool program at a Boys and Girls Club in Virginia, consisted of adolescent focus groups, and adolescents used prototype SPAGAs. As guided by the social cognitive theory and a social ecological model, discussions (n=14; mage=13.4 years) were conducted, recorded, and transcribed. Three researchers coded the data independently, met to review codes, and reconciled disagreements. Consistent across focus groups: 1) identified phone features that could potentially promote PA, 2) most likely to download smartphone applications that were games and to use text messaging, 3) responded favorably to most of the prototype games supported by the smartphones, 4) wanted the ability to compete against others, and 5)#majority wanted a positive/negative point system. Study findings are currently being used to inform the design and development of SPAGAs that are evidence-based, incorporate user preferences, and leverage the smartphone function/feature set. In the future, similar studies could be conducted to inform the development of game-based applications that encourage youth to meet dietary recommendations.