Using digital health applications for health behaviour intervention is becoming popular. Among all application features designed for nudging users' behaviour changes, social support features have received great attention, as social support is shown to reduce patients' uncertainty and improve health behaviour engagement. A variety of social support features have been implemented, but how they are related to app performance, such as app ratings, downloads and review numbers, is unknown. This paper aims to understand the relationship between social support features and these app performance indicators, and identify common ways of providing social support. Three types of social support features have been identified through a review of selected health apps: the support from social networks, from in-app communities, and from health professionals. Apps with social support features are found to have higher review numbers, although not correlate with ratings or download numbers. Potential theoretical and practical implications are discussed, together with the future research plan.