LOL. This is on the todo list :) Thanks for the feedback!

Also doesn't work for Japanese text. It shows pretty much a whole paragraph at a time.

Do you think german words like this would benefit from automatic syllable colorization -- slightly changing the shade of grey to make the syllable boundaries more obvious?

Not sure. E.g. 'Kinderbetreuungsmöglichkeiten' means 'child care possibilities', that's three words in one. I suppose the brain just needs more time to parse that. But just counting characters to determine delay won't cut it, since 'Mississippi' is quite quick to parse.

What 'bout making it simpler and instead of colorizing nouns you colorize a horizontal gradient like http://www.beelinereader.com/

Couldn't you split compound words so the components appear in sequence? e.g.

Kinder- -betreuungs- -möglichkeiten

One could, but most likely one would need a proper morphological analysis[2] to make it work correctly for the endless possibilities to combine words in German. Pretty hard to implement in the browser, but maybe an 80:20 like approach using a good dictionary could help for common terms in combination with slowdown on terms it doesn't know how to split.

[1] for example, one could use wiktionary data and try to extract how to properly separate common terms: https://de.wiktionary.org/wiki/Schifffahrt

Edit: [2] German demo of how that usually looks http://www.tagh.de/demo.php (not affiliated)

Then maybe colorize nouns in a compound noun word instead of syllables ?

For German (and maybe English too?), I think splitting up compound words into their constituent noun stems could work.

Syllable recognition is still an unsolved problem, no? Is anybody familiar with the state of the art?