Not a sketching/design app

Very misleading. You need to purchase lined or textured backgrounds. There is no interface to allow you to adjust brush strokes, pen strokes or anything you would expect to be in an app with the word "sketch" in it.
This is just a file management app that allows you alter an image....meaning you get a black line to write over pictures you download.
Oh, you wanted to use graph paper. Its only a dollar purchase. Didnt i already buy this app???

Bambratt about Sketchworthy - Notes, Sketches, and Ideas