To that end, Martijn, the UI designer, has dropped by Vimeo to provide us with a "sneak peek" at the device's operation, including some demos on iOS and a connected prototyping board, using a custom tool that sends designs to the Pebble screen from any graphics program in real-time (a feature that will reportedly also be available in the SDK).
ENGADGET: Pebble team posts UI preview, provides an early look at how you'll interact with the E-Paper Watch