Traditional medical practice has suffered from male bias, which can lead to sub-optimal treatment options for female patients and increase the incidence of severe side-effects in this population. Mobile health applications, mHealth apps, represent one essential component of the shift towards consumer-centered self-administered individualized health. To prevent sex-specific bias it is important that trials consider sex and gender when developing mHealth apps. We evaluated the inclusion and reporting of sex and gender at all levels in mHealth randomized controlled trials (RCTs). To this end, we conducted a secondary analysis of a large study database addressing the effectiveness of app interventions on clinical outcomes in patients with chronic medical conditions. We followed the 5 steps described in the framework by Arksey and O’Malley and the guidelines of the PRISMA-ScR. Of the 72 app-based RCTs which reported information about sex overall, 62 included individuals of both sexes. The concept of gender was not addressed in any of the studies. The consideration of sex aspects in the design, execution and reporting of mHealth RCTs was minimal or absent. To adequately address the health and preventative needs of the mHealth user population, sex and gender should be systematically included in the research, development and evaluation of mHealth applications.