Objective: Considering increasing demands for mental health services at college counseling centers (CCCs), there is a need for cost-effective solutions that avoid depleting stressed CCC resources. This study examined if ACT Daily, a mobile application based on acceptance and commitment therapy (ACT), could serve as an effective self-guided intervention. Participants: 11 individuals on a CCC waitlist suffering from anxiety/depression participated in the study over 2 weeks. Methods: This study implemented a pre-post, open trial design of ACT Daily. Assessments were completed at baseline and 2-week post assessment. Results: Results indicated that ACT Daily was acceptable and that participants improved on depression and anxiety symptoms as well as psychological inflexibility processes over the 2 weeks. App data further indicated significant in-the-moment improvements on depression, anxiety and psychological inflexibility immediately following skill coaching, with these effects becoming larger over time. Conclusions: Mobile apps like ACT Daily could serve as an effective, pre-therapy tool for depressed/anxious students.