The touchscreen smartphone platform is inherently flexible, giving it the potential to meet the needs and desires of individuals diverse in age and ability. Despite universal design research efforts providing industry with guidance to address this opportunity, current designs fall short. The disconnect stems from differing priorities in design and development and opposing approaches to defining and grouping the user population. The research presented in this dissertation aims to remove these issues from the process of discovering touchscreen smartphone design opportunities. It focuses on users' prior and desired customizations rather than ability- or market-factors. Data were collected on participants' devices' out-of-the-box, current and desired device states along with related stories about their actual and desired device modifications. Template and image analyses identified patterns in the data, which also revealed an underlying structure for organizing and presenting participants' needs and desires associated with smartphone touchscreen customizations. The needs and desires suggest opportunities for industry to shift towards universal design. The structure offers an approach to addressing the gaps between the ability-centered and market-driven approaches to the design of consumer technology.