This essay examines social nudging and influencing factors on user choices on the two mobile apps Foodora and Uber Eats that offer services for food delivery, and whether there are any connections between these factors and the interface design. This type of service has in recent years become popular with the digitization of society. To investigate this, the survey was designed and analyzed based on factors from Fogg's behavior model, as well as categories for interface design from previous research. This study was based on a qualitative research strategy with a focus on deeper descriptions from six selected participants. Data were collected through a test on an interactive prototype combined with a semi-structured interview to achieve the purpose of this study about how digital social nudging affects user choices. The study showed mixed results. The social nudging feature in the form of ratings turned out to have a great influence on user choices, while the feature in the form of popular choices did not. This indicates that some methods of social nudging may be more favorable than others in this type of environment. A new factor was also identified, preference, which turned out to influence user choices more than the social nudging in the form of popular choices. The results also showed a connection between the influence of nudging and the interface design of the apps, as the design may have been influential for whether the social nudging benefits users or not.