Ive always wanted to speed read, but never could focus well enough to be effective. Ive tried training books and websites, but it wasnt enough for me. I tried a bunch of these types of apps on iOS and found Velocireader to be the best! It handles book navigation flawlessly in speed read mode by using one tap pause/resume and double tap to switch between eReader and speed read mode. Theres also a "skip back" button thatll do just that in case you need to go back a bit to reread something that flashed too quickly.
I literally jumped from 200 to 400 wpm by simply using the app (5 words, 0.75 seconds) because it makes focusing on the flashing phrase so easy! And its not confusing to keep up, I feel my comprehension is just as high as reading normally because the app considers the sentence/punctuation when determining exactly what phrase to show (ie: new phrases for each sentence, for each new speech, and paragraph).
I wish for a few more features, though:
1. A timer for minutes to end of the chapter, or end of the book.
2. PDF or we page support.
3. Sync location and books across devices.
A couple tweaks to understanding when punctuation is used to complete a thought and when its not (ie: end of sentence break vs. breaking on Mr. or Mrs.)
loesjoel about Velocireader - Speed Reading for Ebooks