I first heard about Brain Pop when my son came home talking about the video he had watched in school that day. There is a website and an iPhone/iPad app where you can watch video clips about many different topics. Many of the videos are free but some require a subscription which could be pricey ($205.00 for one classroom for a year).
"Both audiobooks and text-to-speech (TTS) can help kids who have reading issues like dyslexia. These types of assistive technology let kids listen to a book being read aloud as they look at the words. But audiobooks and TTS are different in key ways. Use this chart to find out the differences."