Zombie sketches with Paper 53 iPad app

Little by little I'm getting used to using iPad for sketching. Here's some zombie sketches for a recent project. I have some 3-4 drawing apps in my iPad. I try to use them all, but so far the work flow of the Paper 53 app has been the most comfortable for me. It's pretty intuitive. And that's the app I did these sketches with.

... oh, and here's the finished version by the way. It's done in Adobe Illustrator.