The objective of this study was to conduct focus groups with youth (18-29 years old) living with HIV (YLWH) to better understand preferences for mobile applications in general and to inform the design of a mobile health application aimed at improving retention and engagement in healthcare and adherence to antiretroviral therapy. We conducted four focus groups with YLWH to elicit the names and characteristics of applications that they commonly used, reasons they deleted applications, and the features of an ideal mobile health application. A diverse sample of youth (N = 17) with a mean age of 25 years, 88.2% male, and 29.4% African American participated in four focus groups. Positive attributes of applications included informative, simple, allowing for networking, timely updates, little overlap with other applications, unlimited access to entertainment, and with ongoing advancement. Participants identified several reasons for deleting applications, including engaging in excessive behaviors (e.g., spending money), for hook ups only, too many notifications or restrictions, occupied too much space on device, or required wireless connectivity or frequent updates. Participants suggested that a mobile health application that they would find useful should have the ability to connect to a community of other YLWH, readily access healthcare providers, track personal data and information (such as laboratory data), and obtain health news and education. Privacy was a key factor in a mobile health application for all participants. Researchers can use the information provided by focus group participants in creating mobile health applications for YLWH.