BackgroundStudies on which persuasive features may work for different users in health contexts are rare. The participants in this study were microentrepreneurs. We built a persuasive mobile app to help them to recover from work. Representatives of this target group tend to be very busy due to work, which was reflected in their use of the app during the randomized controlled trial intervention. Microentrepreneurs also often have dual roles; they are professionals in their line of work as well as entrepreneurs managing their own business, which may add to their workload.ObjectiveThis study aimed to present users’ views on the factors that hinder their use of the mobile health app that we developed and how these factors could be mitigated.MethodsWe interviewed 59 users and conducted both data-driven and theory-driven analyses on the interviews.ResultsFactors reducing app use could be divided into 3 categories: use context (problem domain–related issues, eg, the lack of time due to work), user context (user-related issues, eg, concurrent use of other apps), and technology context (technology-related issues, eg, bugs and usability). Due to the nature of the participants’ entrepreneurship, which often interferes with personal life, it became clear that designs targeting similar target groups should avoid steep learning curves and should be easy (quick) to use.ConclusionsPersonalized tunneling—guiding the user through a system via personalized solutions—could help similar target groups with similar issues better engage with and keep using health apps because of the easy learning curve. When developing health apps for interventions, background theories should not be interpreted too strictly. Applying theory in practice may require rethinking approaches for adaptation as technology has evolved rapidly and continues to evolve.Trial RegistrationClinicalTrials.gov NCT03648593; https://clinicaltrials.gov/ct2/show/NCT03648593