Filterstorm will get many of the changes in Filterstorm Pro in the version 3 release (free update). To see which one is best for you, I suggest looking at this page.
http://filterstorm.com/pro/fspro-vs-fs
Tiny link: http://taii.cc/4W
Tai Shimizu is owner of Stormy Imaging and author of the iPad/iPhone photo editing App Filterstorm, the drawing app Inkist, and the Mac HDR app Light Compressor