MeasureThis 1.0 app for iPhone and iPad

Measures areas, perimeters and distances anywhere in the world. Set way points, points of interest and comments on any marker. Can also quickly measure distances from current location or reference point. Can also store markers to be used at a later time. Markers can be moved to precise locations using an address, coordinates, current or stored locations. Areas and perimeters can be measured by walking, driving or moving around an arbitrary path.

Note: Continued use of GPS running in the background can dramatically decrease battery life.