When using the app on my 9.7" iPad Pro with Apple Pencil (1st gen), there's a visible lag between the pencil tip and the "line" being drawn (it usually is less noticeable if I use the clear interface). Sometimes there are missing strokes that appear only after raising the pencil from the screen (probably because of the line smoothing).

It would be nice to have a more fluid input to make it more realistic (I'm just "complaining" because other drawing apps work perfectly fine with this setup).