As excited as I am to see drawing keyboards with iOS 8, I like Jot better. Scribble Board has nice background colors, but being able to control transparency is missing and I cant get layered images with Scribble Board. I also am not a fan of the built in ABC keyboard - switching isnt faster and Id rather not give this app access to my alphanumeric keystrokes.
Lou Art about ScribbleBoard for iOS 8 - Keyboard to draw your messages