Self-tracking tools can support health awareness and behavior change, though sustaining engagement remains difficult. Prior work has explored qualitative visualization, customization, and collaborative features to promote engagement; but little is known about how these strategies interact when combined. We present Sprout, a mobile application that integrates qualitative, customizable, and collaborative health tracking using a garden metaphor. Sprout allows users to choose what they track, customize how data is visually encoded, and participate in anonymous communities where collective progress unlocks shared features. In a 2-week field study with N=22 participants, users reported that qualitative displays worked best as a complement to quantitative tools, customization mostly happened during app setup, social features were the most engaging though collaboration produced both motivation and frustration, and anonymity protected privacy but limited social connection. Our findings show how multiple design strategies coexist in one system, sometimes competing and sometimes aligning in supporting users' tracking needs.
ACM CHI Conference on Human Factors in Computing Systems