Is it possible to export out .icn from Sketch 3 or Affinity Designer?

I currently on a trail with Sketch 3, but don't see the option for .icn or .icon.

Looking to export out SVGs http://ift.tt/1OpcvhK into .icon files for my app icons.

Haven't checked out Affinity Designer yet, but really looking forward to have these 2 new modern apps replace my old Adobe workflow, and not have to pay monthly :)