The download button opens the iTunes App Store, where you
may continue the download process. You must have iTunes installed with an
active iTunes account in order to download and install the software. This
download may not be available in some countries.
From Jose M. Quinteiro (IUMA-ULPGC):
Long time exposure photography involves using a long-duration shutter speed to sharply capture the stationary elements of images while blurring, smearing, or obscuring the moving elements.Long exposures are easiest to accomplish in low-light conditions, but can be done in brighter light using neutral density (ND) filters.This app allows you to have two different areas with different light conditions, giving you the correct exposure time for each dark and light area, depending on the ND filter you want to use.