if your browser is set to English, you may see a "Proofread by an Expert" button on languagetool.org. This is a test to see if our users are interested in human proofreading. The test will probably run for at least a week. If it works well, we might extend it to other languages.
If you don't see this button and want to give it a try, visit http://languagetool.org/human-proofreading and then languagetool.org (this will set a cookie so you're in the test group, no matter what language your browser is set to).