When I told my 4 yr old's Occupational Therapist about his aversion to handwriting, she recommended an ios app for him to practice "writing" his letters. It is about $5 at the app store. He loves it! It shows them the proper way to trace it, doesn't let them do it the wrong way, and has them progress from easy, to more difficult tasks. There are cool sounds and graphics, which capture my super active child's interest. Definitely worth it if you have an ios device and a little one who needs lots of stimulation.
http://www.letterschool.com/