The present study examined how the use of a mindfulness app affects compassion and mental health, specifically depression. Participants were randomized to a mindfulness intervention or waitlist control. We predicted the intervention would increase self-compassion, which, in turn, would decrease depression (i.e., self-compassion would act as a mediator). Further, we expected the intervention would increase compassion for others, which would decrease depression. Self-compassion mediated the relationship such that the intervention predicted increased self-compassion, which predicted decreased depression. Compassion for others did not significantly mediate the relationship. Findings provide evidence for an everyday tool to improve self-compassion and psychological well-being.