The smartphone exemplifies the rhetorical smart city movement. This paper examines one potential use of smartphone technology—mapping public transportation services in a megacity of the Global South. We examine the potential user impacts of introducing a smartphone-generated and analogue-delivered schematic bus map in Dhaka, Bangladesh. After distributing the map, we used a web-based survey to investigate impacts on users’ knowledge, as measured by their stated understanding, navigation and perceptions of the system. While a small and biased sample, the results suggest that the map fills a knowledge gap, provides useful and valued information and may stimulate ‘exploration’ of the city and its bus system.