GrammarBase.com

===My experience using it and how it could be useful: This tool is very easy to use and navigate. This could be useful in my classroom for my students to check documents before submitting for grading. I am always urging them to proofread before they submit, but usually its just changing whatever spell check happens to catch. This tool would find additional errors that may not be evident to spell check.===

===What a user would need to know when signing up for the tool: It is not necessary to register on this sight. You simply type or paste in the text to be analyzed, and it returns a simple report listing changes that need attention.===