The staff at Sector 7 have developed several useful CGI calculators. None are very complicated, but are meant to simply save time.
This calculates the positions of the Bragg peaks for given crystal structures and either a fixed photon energy or fixed scattering angle. A table of common crystal parameters is here.
Eulerian <--> Kappa geometry converter
This shows the corresponding angles between the Eulerian and Kappa geometries.
This shows the coherent properties of the X-ray spectrum at a certain distance.
This calculates the expected speckle size for a given experimental setup.