Except after C, of course.
Replaces all occurrences of "ei" with "ie", and all occurrences of "cie" with "cei". Why? Because it's just not right. Rules are rules, and this is a big one. If you're going to make a special rule for it, you can't just keep making exceptions here and there. You have to be committed. I before E, except after C.
Download on the Chrome Web Store: https://chrome.google.com/webstore/detail/i-before-e/lcalildlcnhcpbephggipadcgpajjeek