JustSketchMe is a really nifty tool. Loads of posable characters available to use as drawing, sculpting and storyboarding reference. The characters are easily posable and the paid app comes with so many preset poses which is great for days when I'm feeling uninspired. I love that you can add multiple characters to the scene and save poses. The props tool is pretty cool for creating lo-fi shape reference for things like tables and hand props. I'm super impressed!