This journal article describes a study with the objective to develop a mobile app, called YTH StreetConnect, to support homeless and unstably housed (H/UH) youth and their providers in accessing health care and vital resources. In Phase I, the researchers conducted a literature review on mobile phone and internet usage by H/UH youth and interviewed H/UH providers to inform the app prototype development process. In Phase II, they conducted focus groups with H/UH youth participants to test the usability of the YTH StreetConnect app. From the usability testing, participants proposed improvements to the app, including visual updates to the user interface, map icons, new underrepresented resource categories, and the addition of a peer-rating system. The study found that YTH StreetConnect is a promising way to increase service utilization, provide referral access, and share resources among H/UH youth and providers. The feedback garnered from H/UH youth and providers offers insights on how to improve future models of YTH StreetConnect and similar programs that assist H/UH youth.