The purpose is to help people to be better at spelling, but mainly to save the dying art of handwriting.
The pen itself has a special version of Linux on board.
While the pen's software will be closed source, the API will be open sourced so others can write software for the pen.
Here's a picture that shows the guts of the pen:
Besides it's educational properties, the pen also can save handwritten notes as computer images and can also save them as text for future use.
Here's the story behind the pen's birth:
"Lernstift inventor Falk Wolsky explains that the idea was born out of frustration with his oldest son’s homework mistakes. Wolsky says his son was too often distracted, and would make small, preventable errors.
“My wife said: ‘I wish the pen would give him an electroshock or something to make him think about his spelling,’” Wolsky says. “I thought, an electroshock wasn’t so good, but a vibration might work.”" -Wired.com