Grammarian PRO3 - Grammarian PRO3 is a feature-rich grammar checker that enables you to write better content without taking assistance from the English teacher.
Pili Pop - Great language learning method for kids
LanguageTool - Free proofreading tool for OpenOffice, LibreOffice, Firefox, and Chrome.
Litnerd - The Pixar for education, reading program for K-5 schools
Gramlee.com - Online grammar check, proofreading and copy editing services.
Wikids - An encyclopedia that talks to your kids