Objectives: College counseling centers face significant challenges meeting the mental health needs of their students and waitlists are common. Mobile apps offer a promising solution to increase access to resources while students wait for services. Methods: This pilot randomized controlled trial evaluated the feasibility and acceptability of a publicly available mindfulness app. Students on a counseling center waitlist (n = 23) were randomized to use the app or not, with assessments completed over four weeks. Results: Recruitment over three semesters was slow, leading to an underpowered trial. Participants reported high satisfaction and moderate app usage. Very preliminary support was found for potential app efficacy relative to the control condition, particularly for depression, anxiety, and overall distress. Weaker, mixed effects were found for mindfulness and values processes. Conclusions: Overall, these results provide mixed findings suggesting the potential benefits, but also challenges in using a mindfulness app for students waiting to receive counseling services.