As mobile health apps become increasingly influential in daily life, they present an important opportunity for health communication for disease prevention. User impressions of app designs are influential for adoption. Using cues to increase feelings of being with others (social presence) is one way to encourage favorable impressions and health app adoption. To examine the impact of social context cues (conversation cues vs. community cues vs. no cue control) on two forms of social presence (emergent and transcendent social presence), we conducted an online experiment (n = 587) with US adults. We also examined the indirect effects of conversation and community cues through social presence on app trust, perceived ease of use, perceived usefulness, and intentions to use the app. We found that conversational cues elicited intended feelings for new, emergent interactions and that community cues increased perceptions of ongoing or established social formations for transcendent interactions. These cues also had positive indirect effects for increased trust, perceived usefulness, and intentions to use the health apps and should be considered when developing mHealth to improve uptake and delivery of health promotion online.