virtual Photographer by optikVerve Labs has been one of my favourite plugins for B&W conversion. While providing a link to a new member on another forum I noticed that they now have virtualStudio. It is a free photo editor that now includes virtualPhotographer. (vP is still available as a PS et al plugin). It does the basic editing tasks and includes Curves and Histogram. There is a Frame app and a quick and easy Watermarking app. At the price its a must have. LINK.