Through my doctoral research, I aim to gain a deeper understanding of how LBPHDs, location-based, post-hoc data applications, can be leveraged to support urban communities. From a case study of a dating app that utilizes shared location history, happn, we showed that LBPHD information was meaningful in building interpersonal relationships. Based on these findings, we designed MoveMeant, an application that extends LBPHD from interpersonal to community-level information sharing. A pilot study suggested the potential of MoveMeant to increase local community awareness through dissemination of local knowledge and discovery of third places. We extended the findings from the pilot study to a large-scale field deployment of MoveMeant across three different communities. Using a research through design approach, we interviewed leaders of the communities in which we deployed MoveMeant to gain an understanding of the social structures in which we introduced the technology. Our findings suggest the potential warranting power of LBPHD to strengthen local ties, but also the risk of users interpreting the data to indicate differences within a community, an effect we call surfacing. Our findings offer design implications for community apps. Future work could determine if design might be able to overcome the effects of surfacing.