This is really cool! I've tried speed reading apps before but they always felt unnatural. 900wpm is impressive if it maintains comprehension.
A few thoughts after trying it: - The visual design is clean and doesn't distract from reading - Would love to see reading comprehension tests built in (to verify you're actually retaining at 900wpm) - Maybe add a "warm-up mode" that gradually increases speed?
The viral aspect is smart - people love sharing their WPM scores. Have you thought about adding a leaderboard or social sharing features?
Great work on this! Bookmarking to use for catching up on long articles.