Rewordify.com simplifies difficult English. The learner can enter hard sentences (or whole chapters or a webpage) into the site and instantly sees an easier version, for fast understanding. All of the reworded words are highlighted and you can click them to hear and learn the original harder word. You can change how the highlighting works to match the way you prefer to learn.
Often people with print impairments find dictionaries to be confusing and may find Rewordify's definitions helpful, they change to match the original word or phrase's part of speech, verb tense, and singular/plural form, so they make sense.
The service is free and available online at http://rewordify.com/