RealBasic Screen Capture Program

We are looking for someone to develop a stand alone screen capture program. This program would have to be cross platform and run on both windows and Mac OS. We have previously developed our own application in Visual Basic and would like to re-create a similar program in the RealBasic language. This program would take a snapshot of the screen and then allow you to crop that image. Once cropped it would place the image on the clipboard or have an option for saving the image as a .jpg. We would also like an undo button, to reverse the cropping process if a mistake is made. The final caveat would be for it to work on multiple monitors. If you launch the program from monitor 1 it captures monitor 1's screen, if ran from monitor 2 it would capture monitor 2's screen. Below is a link to a video showing how the previous visual basic application functioned. [login to view URL]