Older adults are increasingly savvy consumers of smartphone-based health solutions and information. These technologies may enable older adults to age-in-place more successfully. However, many app creators fail to do needs assessments of their end-users. To rectify this issue, we involved older adults (aged 65+) in the beginning stages of designing a mobile health and wellness application. We conducted a participatory design study, where 5 groups of older adults created 5 designs. Four groups identified at least 1 health metric not currently offered in either the iPhone app store or the Google Play store. At the end of the sessions we administered a questionnaire to determine what health topics participants would like to track via smartphone or tablet. The designs included 13 health topics that were not on the questionnaire. Seventeen of eighteen participants expressed interest in tracking health metrics using a smartphone/tablet despite having little experience with these devices. This shows that older adults have unique ideas that are not being considered by current technology designers. We conclude with recommendations for future development, and propose continuing to involve to older adults in participatory design.