Over 100 million adults in the United States have hypertension. The DASH (Dietary Approaches to Stop Hypertension) eating pattern is an evidence-based first-line treatment option for hypertension; however, adherence to the DASH eating pattern at a population level remains low. To address this gap, we will implement Nourish, a randomized controlled efficacy trial that will leverage a commercially-available smartphone application and evidence-based behavior change principles to improve adherence to the DASH eating pattern among adults with hypertension.