To read faster you need to develop both your eye muscles (the tiny sets of muscles that enable your eyes to move quicker, meaning you can scan text faster). The other element is the mental approach.
The App is designed to help develop the physical characteristics – in short sending your eyes to the gym!!
The App has a book and the idea is to gradually increase the pace at which the screen covers over the text – try to keep about three lines ahead of the screen and every minute or so increase the speed a little to make you work those eye muscles a bit more to keep ahead.
Search for Read Faster in Play Store – try it out for free then get loads more