Great App!
I have a couple of requests...
1) The biggest one is to have an option of "Do not cross top layers".
When I print a model that has a nice flat surface on the top, the print head will sometimes cross my nice flat surface and leave a drag mark across it. This only needs to happen when the flat surfaces is at the same height (or say within 2 layers) as the extruder. I don't mind if it has to make a big wide circle around the part to get to the other side.
2) A speed optimization would be to have it start the perimeters at the end of infill.
Maybe a setting I'm missing, not sure, however, I've seen it where it finishes with the infill, then travels all the way to the opposite side of the model to start drawing the perimeters again. It would speed up the prints if it just started where it was.