" Grammarly Lite is a spell checker for Chrome, Firefox and Safari Browsers. There are several extensions for checking spelling mistakes and Grammarly promises to do better than others by doing some extra things like contextual spell checking.
"Features of this extension include contextual spell checking Grammar check, Punctuation correction, Synonymous suggestion, Dictionary & Thesaurus. It works anywhere on the web whether you are writing an email, a blog post or updating status on a social network site. …"
Source: Technology Bites
More Grammarly Lite: Spell Checker for Chrome, Safari and Firefox