Rewordify.com | Understand what you read
Paste difficult to understand text into the yellow text box, and this website will give you a simplified version. While this is intended for people learning English vocabulary (or teachers helping students), it might be helpful as an instructional designer. It doesn't do anything for absurdly long sentences (in fact, sometimes the simplified version is longer), but you could use this to take a first pass edit on complex SME language.
