Lichen App for assessing Nitrogen pollution

This mobile app is a tool for assessing the status of nitrogen in your area by surveying lichen on trees. By identifying the presence or absence of 9 nitrogen sensitive and 8 non-sensitive lichens on tree trunks and branches you can get an estimate of how polluted your area is.
Author(s): 
CEH
Free: 
Yes
Available as: 
Online
App