In the context of high divorce rates, declining relationship satisfaction over time, and associated negative outcomes for individuals and families, the prevention of relationship dysfunction and the strengthening of partnerships are of increasing relevance. Considering the growing digitalization and the rising mobility of family members, Internet- and mobile-based delivery of systemic couple therapy gains importance. This chapter describes a user-centered development process of a digitalized implementation of systemic couple therapy using Couple Time, an Internet- and mobile-based systemic intervention for distressed couples. The example of a focus group and usability study with distressed couples illustrates how a user-centered development process of systemic Internet- and mobile-based interventions can be conducted. Several aspects regarding acceptance, usability, aesthetics, and content were detected that need to be considered when designing such an intervention. Upon reflection, digitalizing systemic therapeutic interventions and principles poses a significant challenge. However, systemic Internet- and mobile-based interventions for couples have the potential to address existing gaps in mental healthcare and mitigate the long-term psychosocial and economic consequences of relationship dissolution.