The Affectionate Gesture Planner (AGP) is a smartphone application (i.e., “app”) that aims to increase relationship satisfaction for couples in long-term relationships by prompting couples to complete loving acts for each other on a daily basis. The AGP app is informed by concepts from social exchange theory and the investment model (Rusbult, 1983), which predict that increasing the mutual exchange of beneficial investments to the relationship improves the quality and stability of the relationship. The present study is a formative evaluation on the prototype of the AGP app. Based on participant feedback, the AGP app will be improved prior to future trials. Future models of the AGP app will be used to compare the efficacy of using standardized suggestions versus personalized prompts.