[pinkyand]

Have you tried something like f.lux ? it can remove the black spectrum of colors from computer/tablet displays ,and they claims there's research that this is the spectrum most critical for messing up with sleep.

With regards to eink web-apps, don't forget you'll also have to fight the keyboard if you'll even get one. So it's hard to design to that medium. On that note, there's the onyx eink phones/tablets that have a version of the play store, but their only unique apps are rss reader and google calender. But maybe sniffing around onyx and their users will let you discover usable apps.