Grammarly is a leading edge proofreading editor that corrects contextual spelling mistakes, grammar errors, and helps you with your vocabulary.
You can download the OS X application or Microsoft Word add-on, and use Grammarly right on your computer, and/or takes it one step further, by integrating it with your browser through an extension. This allows Grammarly to be available anytime you type something on your computer or the internet. So that every time you post to Facebook or Twitter, you'll get a quick confirmation that the sentence you just wrote is grammatically correct; from just a simple click of the mouse. It does this by using sophisticated and powerful algorithms that scans your content as you type it - in real time.
There is a Free version and a paid version. Although the free version is good for most people, the paid or 'Premium' version as they call it, gives you access to things like:
- over 250 grammatical error checks
- vocabulary enhancements
- plagiarism checker
- citation suggestions
I have been using the 'Premium' version for a week now, and the only downside for me is that they don't have a smartphone or tablet app.