Apparently the Autodesk SketchBook Pro (and Express) can open Wacom Inkling file natively. If you want to keep the drawing in bitmap format, better open it in SketchBook Pro/Express.
With one sketch file from Wacom Inkling, we can create tons of brush tool variation. You draw with (Inkling) ballpoint on a paper, end up as pencil on SketchBook Pro/Express.
More info about SketchBook + Inkling
here.