App-based habit building has been shown to be a good tool for forming desired habits; however, it is unclear how much individual features that are present in many apps contribute to the success of habit building. In this paper, the authors consider the influence of social support features by developing an app in which habit progress was shared with peers -- 'buddies' in the app. In the study, 38 participants created habits and monitored their progress regularly with the app over three weeks. The participants were divided into a control group without a 'buddy' and a treatment group cohort in which they were assigned to buddies based on their desired habits. With each habit repetition, the app gave feedback on the number of repetitions and the automaticity of the user's habit. The results obtained show that the reproduction of app-based intentional habit building is effective and that automaticity could be predicted by habit repetition.