Shifty Spritz is my own implementation of http://www.spritzinc.com/. I made it because I struggle reading fast. I found that the Spritz reader was perfect for me as I was able to read fast and with great comprehension. Although I found that Spritz and similar readers where to clunky and slow, so I decided to spin up my own. Shifty Spritz Speed Reader is open source and you can view all the code on https://github.com/andrewmilson/shifty-spritz. I hope you love using it as much as I do!