From David Jade's website: http://tinyoctopus.net/ExpoDev/
Originally Posted by LJH
"BTZS ExpoDev is the newest generation of ExpoDev for Apple iOS devices. As a companion app for BTZS Plotter, ExpoDev allows you to use your BTZS Film Profiles to accurately calculate B&W film exposures in the field for consistently exposed negatives that are easier to print in the darkroom. ExpoDev was designed for Large Format film photographers working in any traditional or alternative process (including hybrid processes such as film scanning/digital printing)."