There are lots of drawing apps, but nothing quite like that one. If you want a drawing app then the best one I've found (though I'll admit I haven't tried many) is Scratchpad. It's free, has 12 color options, undo/redo, different brush sizes, and export to JPG. I'm sure if you looked at all apps you could find a better one though.
I like the app DrawBook - it even lets me open photos from my phone (when bridged) or playbook and draw on them. it has an eyedropper for picking up colours and a slider for pencil size. also a paint bucket and eraser function. saves the files as .PNG
Lots of good free drawing apps out there. There was one that I downloaded to play with, but it was way more advanced than what I would ever use. I'm not into photoshopping and drawing. Unfortunately, I can't remember the name of it to save my life.