Inkcase is exactly what you just guessed it is: a phone case with an e-ink screen that provides a simpler, more economical view on your communications.
inkCase i6 adds an 4.3 inch E Ink display to your iPhone 6, adding conveniences and better readability. inkCase i6 connects wirelessly to your iPhone 6 through Bluetooth, allowing you to access contents without switch on the iPhone’s display. Reading on inkCase makes your reading more enjoyable with the paper like display quality and helps you conserve your iPhone’s battery.
inkCase Now is an info center that facilitates push notifications, weather updates and email from the iPhone to the E Ink device. The always on display ensure you will not miss another important notification; messages, news and other notifications are push to inkCase’s always on E Ink display the inkCase Now.
I'm not sure. I love the simpler, monochrome display. But I want a phone that has one, not a case I put my normal phone inside.
If you want phone hardware that's "more minimal," adding another screen to the one you've got seems to miss the point. And if you're not into the e-ink display thang, you could just get an app that does the same thing. I don't really buy that there is a battery-life angle here, because the kind of things e-ink is good for—notifications and reading plain text—don't drain much battery life in the first place.
Three e-ink phones of note: The YotaPhone2, which actually has a normal screen as well and is $1,000; the Onyx Book, which is "out of stock" and reportedly useless for calls; and the Moto F3, a genuinely wonderful $20 candybar that is sadly too obsolete to be much use even for dumbphone aficionados like me.
