1. Check this option to enable all selected snap options.

2. This will snap only to points created by the PlanSwift digitizers.

3. This will enable PlanSwift to snap to  points created in CAD files.

4. This option enables you to snap to a point, but if you hover at that point for a second or two the red snap box will turn green, thus locking on that axis.

5. Ortho will lock the digitizer on the 90 degree and 45 degree axis.

6. This option allows a bit more refinement: snapping to the 90 and 45 degree axis only when you are within a few degrees of them.