Chrome: We've seen some solid apps for speed reading on mobile, but if you're not interested in reading on your phone, Spreed is a Chrome extension that offers a similar experience.
Spreed uses a technique called subvocalization to enable faster reader. With Spreed, you select the text you want to read, right-click it, select "Spreed selected text" and you'll see a popup with a speed reading app ready to go. When you click "Play", Spreed starts running through each individual word of text. You can tweak the speed, amount of words and font size to make it easier to read. It's not the prettiest-looking interface, but it gets the job done.