OpenTreeMap is a web and mobile (iOS and Android) application for collaborative urban forest inventory. The software can also calculate ecosystem benefits (air quality, stormwater infiltration, energy savings, and carbon sequestration) for any tree. The result is an interactive map and database of all of the trees in a community as well as a profile for each tree, including planting and stewardship details.
Project web site: http://opentreemap.github.io/
GitHub repo: https://github.com/azavea/OpenTreeMap