Soft Edge lets you sculpt your drawings. Think ZBrush or Blender's sculpt brushes, but for 2D.
Traditional drawing apps like Photoshop record how your stroke looks. You pick a brush, you draw, and the mark on the canvas is, for all intents and purposes, frozen. You can massage it with warp or other tools, but you're distorting the brushwork and it's not very precise.
Soft Edge keeps every stroke alive and sculptable.
