Emotions and worries can reduce individuals’ available attention and affect economic decisions. In a four-week experiment with 2,384 US adults, offering free access to a popular mindfulness meditation app that costs $13 per month improves mental health, productivity and decision making. First, it causes a 0.44 standard deviation reduction in symptoms of stress, anxiety, and depression, comparable to the impacts of expensive in-person therapy, with improvements even among participants with minimal or mild symptoms at baseline. Second, it increases earnings on a proofreading task by 1.9 percent. Third, it makes decision-making more stable across emotional states, reducing the interference of personal worries with risk choices. Overall, our results demonstrate the potential of affordable mindfulness meditation apps to improve mental health, productivity, and the impact of emotions on economic decisions.