Sketchology, Popsicolor, Procreate.
Sketchology is a newish drawing program which uses vectors, so the drawing is infinitely scalable. Needs a few tools just yet, I’d like the marker to work in multiply mode, or have a layer or two to put it behind the lines. Textured vector lines are cool, something that Adobe Ideas should have. For instance the line drawing could have been done even in Sketchtime, with quick marker tones in Sketchtime, set to multiply, or on a layer behind. Sketchology has a watercolour brush and a calligraphy pen, thin and fat like the one in Paper.
In fact I could have done the thing in Procreate alone, except for the scalable vectors, or even wholly in Sketches once again except for the vector scalability. The zoom in Sketchology is smooth and quick and precise, and actually very nice to use. And even as this drawing looks so casual, I did zoom for detail.