Storyboard test done with Storyboarder, by Wonder Unit. Storyboarder is an app designed with constraints that are optimized for storyboarding. It focuses on the essentials, drawing shots. With just a few tools, its interface is toy-like and very intuitive. The drawing feel is good. Among other things you get a quick and PDF layout export. It also has a simple timeline so you can use it to build basic animatics
Definitely recommended for storyboards.