To be successful mHealth applications must be consistent with the way individuals use technology. Using qualitative methods and an iterative approach that blends consumer-driven and investigator-driven aims can produce paradigm-shifting, novel intervention applications that maximize the likelihood of use by the target audience and their potential impact on health behaviors. In behavioral health the development of mHealth applications often takes a top-down approach driven by the investigators and programmers, with relatively little input from the targeted population. Often user-input is limited to "like/dislike" post-intervention consumer satisfaction ratings or device/application-specific user analytics. To have a lasting effect on health behaviors it is crucial to obtain user input from the start of each project and throughout development. This paper describes the use of qualitative methods in an end-user participatory framework, and demonstrates how this lead to important changes in our approach to health interventions delivered through mobile technologies.