“…Although research is just emerging, app users tend to: have lower HIV testing rates (Sun, et al, 2015; Rendina, et al, 2014) and higher numbers of sexual partners; (Sun, et al, 2016; Phillips, et al, 2014; Young, et al, 2013; Landovitz, et al, 2013) and be more likely to report: sex with both men and women (Sun, et al, 2015; Rhodes, et al, In press), alcohol and drug use during sex (Beymer, et al, 2014; Young, et al, 2013; Landovitz, et al, 2013; Winetrobe, et al, 2014) unprotected anal intercourse (Landovitz, et al, 2013; Winetrobe, et al, 2014; Rhodes, et al, 2015), and a sexually transmitted infection (STI) history (Beymer, et al, 2014). In addition, it has been suggested that some app users are “hard to reach” because they may be less likely to: be exposed to venue-based prevention efforts (e.g., those that are in gay bars/clubs or community based), disclose same-sex behaviors and sexual risks to health providers, identify with gay-focused prevention messages, and may have challenges engaging in HIV-related care (Rhodes, et al, 2014; Bull, et al, 2014; Holloway, 2014; Holloway, et al, 2014; Noar, et al, 2012; Lewis, et al, 2011). …”