[Guidelines for the Design of Mobile Apps in Smart and Sustainable Districts].

Today, two-thirds of global energy demand and 70% of all carbon emissions originate from cities. These figures offer high potential for addressing climate change through targeted measures in urban areas. The construction or renovation of energy-efficient buildings, innovating mobility concepts, sustainable energy supply or concepts for incentivizing residents help to make cities more sustainable and climate-friendly. The services required in this regard can be supported and mapped digitally by so-called mobile district apps. Mobile district apps help residents of smart cities to shape their everyday behavior in a more climate-friendly and sustainable way, can digitally map classic services, and connect residents with each other. Existing mobile district apps are usually individually tailored to a smart city district and address a goal from one of the areas of sustainability, services, or community. This article brings all target areas of mobile district apps to a generic level and presents nine guidelines to support urban planners in the design and development of mobile district apps. The guidelines highlight the dimensions of user-centricity, data privacy, and economic feasibility. All these areas intertwine when developing mobile district apps and need to be considered for successful implementation. The article describes the realization of the guidelines using an app from the cooperative research project Stadtquartier 2050 concerning sustainable cities as an example. In this project, the residents of two demonstration districts in Germany are to be supplied with energy in a climate-neutral way. The app provides tools for analyzing and benchmarking users' energy consumption behaviors, as well as educating residents on how to live more climate-consciously.