Fresh Paint
This is Microsoft's original sketching and drawing app and it still is a mainstay for anyone who wants to use their pen to draw on their device.
"We believe that brilliant, creative ideas can come from anyone, anytime. It’s time to set your creativity free. Create original artwork, turn photos into beautiful paintings, or choose an activity pack to help you get started quickly. From whimsical pictures of your friends to amazing landscapes, Fresh Paint enables you to create anything."
Download Fresh Paint from the Windows Store