Skritter is designed to help you learn to write Japanese (kanji) or Chinese characters.
As well as the Skritter website there are i-pad, i-phone and android apps.
The apps, naturally, cost money, but there is a demo page on the website which give a good idea of the basic package and, if you decide to sign up, there is a weeks' free trial during which you can cancel your subscription.
Skritter is not the same as picking up a pen and actually writing, but it is good fun and saves paper!