Check out the Ramani Huria (Swahili for Local Map) project in Dar es Salaam. Ramani Huria is a community-based mapping project which has trained university students and local community members to map the most flood-prone areas of their city.
To carry out this mapping activity different technologies and data collection methods were applied. Field papers, grabbing GPS units, data collection forms, and intuitive phone applications (OpenMapKit & OpenDataKit Apps) that are equipped with imagery and forms for direct data collection, were used. Additionally, low cost drones to produce aerial imagery and other methods to produce street view imagery were made use of. If you are interested to know more about Ramani Huria visit: http://ramanihuria.org/ and watch the video below.