Just back from life drawing at Swansea Print Workshop and I did this on my Samsung Galaxy Note 8.0 (8 inch) using a free Markers app. The pose was 25 minutes long. Very tricky foreshortening, really hard.
With this app, I need to put in a solid background before drawing so I usually lay down an opaque white ground with my finger and then overlay with a translucent light grey and then a translucent beige and finish off with an airbrush white. Then I switch to the stylus and start to scribble. If you don’t put in a background, when you save it, you get weird stuff going on like the background goes black and some of the drawing switches to negative. Then you have top export it into something like Adobe Photoshop to correct it. It took me a while to work that one out. Much easier to lay in a background colour.
scribblah 
very interesting use of colour Rosie!
Just what the machine threw at it lol
This is super cool, but I gotta say I dig your traditional sketches more than your digital stuff.
Yes, I prefer to work traditionally but I force myself out of my comfort zone to avoid becoming formulaic. Using digital media makes me focus on other aspects of what I’m drawing because of the limitations and differences to what I normally use.
Nasty bruises there! Did she ‘fall down the stairs’ while in police custard? Some have turned to gangreen!