Creaceed is offering a special version of Hydra, its HDR photography application, in the Mac App Store: Hydra Express. It costs US$49.95.
The original version of Hydra is now dubbed Hydra Pro and costs $79.95. All registered users of the original Hydra 2.x are now registered users of Hydra Pro 2.x.
Hydra Express lets you input up to three images. Hydra Pro lets you input up to 10 images, offers Input and Output filters, and Aperture and Lightroom plug-ins. The pro version is only available at the Creaceed web site (http://www.creaceed.com).