Good try, keep going The aperture setting is far too coarse - it needs to be in 1/3 of a stop, in line with modern cameras. The lens focal length setting also is too coarse. It has to be in 1mm steps. Subject distance - the same, should be in 1m steps say to 10m, then say 5m steps to 50m, and so on. The UI is nice and not cluttered like some other apps. Personally I would put the DoF result at the bottom. What is more important is the near limit and the far limit. For people who use custom CoC, the crop factor is superfluous and misleading. It has to be set to 1 for the calculator to calculate correctly. Crop factor 1 is for FF DSLR ??!! My cam is m43. In any case, it should be set in options and not on the main screen. Good luck.
This is a really user friendly tool that does exactly what it should do! I recommend this tool.
Added a lot more crop factors. See http://www.dpreview.com/products/cameras for yours. Any missing? Let me know and we will add them.
Added feet and yards as units for distances.