mHealth devices and applications, with their wide accessibility and ease of use, have the potential to address persistent inequities in biomedical research participation. Yet, while mHealth technologies may facilitate more inclusive research participation, negative features of some unregulated use in research — misleading enrollment practices, the promotion of secondary mHealth applications, discriminatory profiling, and poorer quality feedback due to dependencies on biased data and algorithms — may threaten the trust and engagement of underrepresented individuals and communities. To maximize the participation of currently disenfranchised groups, those involved in unregulated mHealth research must become aware of potential risks, adopt targeted education policies, audit algorithms for hidden biases, and engage citizen scientists and other community members to identify and forestall possible harms.