weird if I load a model that is off the platform flshprint asks me if I want to move it to the platform, say yes and it's on the platform.
You can also mmove it about manually. select the print, then click the 'move' option on the left.
And either click the 'om platform' button or manually lower it with the z-axis control.

@perot - short of adding g-code, commands flashprint will do pretty much everything simplify3d does.