'Pitstop' made with Sketch Time App on an iPad

While doing a search for Sketch apps the other day, I stumbled onto this app called Sketch Time, http://sketchtimeapp.com/ which turns out to be fairly brilliant in how much it's boiled down sketching to a small but powerful toolset. The app is very fast using your finger (I have not tried with a stylus or brush yet) and the UI allows for fast navigation through various pen or marker sizes...though in my opinion, it favors those who have used real-world markers for a long time, or been trained to use thes in art or design school. There are no controls for the opacity on the markers, but the bleed on the markers is fairly realistic.  The app also allows playback, though I cannot see how to export these files. I made my own cheat with AirServer and a screen recording app on my PowerBook.