Grammarly Spell Checker & Grammar can check your online communication. This browser extension helps you write clearly and confidently on Gmail, Facebook, Twitter, Linkedin, Tumblr, and nearly anywhere else on the Web. With Grammarly, you can always be sure that your words are mistake-free and say what you mean.
Free open source TeX/LaTeX-Aware spelling checker.
Puts at your disposal a large collection of writing tools.
A powerful tool for testing your spelling skills, complete with Hangman game.
Open source spelling service for Mac OS X based on Hspell.
Defeat the evil witch that has cursed a whole kingdom.