%Cover is an environmental application designed for use on iOS devices. It utilises standard smart phone technology (such as camera, GPS, date/time) to apply existing assessment techniques, used by environmental professionals, students and amateurs, in the ecological assessment of vegetation cover; i.e. the amount of canopy leaf cover versus leaf gap, above a nominated point along a transect or under an individual tree. The amount of leaf cover is expressed as a percentage value and is a commonly used metric in the environmental monitoring, classification and condition assessment of vegetation communities. The existing field practice for estimating the percentage of canopy cover is to visually assess the canopy cover using a hard copy reference sheet, with black and white images showing incremental area increases of 10%; from entirely white (0%) to entirely black (100%). %Cover was designed to be a simple digital application of an established scientific method for the measurement and monitoring of leaf canopy cover. Smartphone technology provides a platform for the collection and analysis of environmental monitoring data, therefore minimising the amount of specialised field equipment.