I am surprised no one has mentioned E Ink phones. My daily driver is an E Ink Hisense A5 phone that is modified to run Google Play. It can run all Android apps without any major issues.
The E Ink display has two advantages over LCD: it consumes very little power and it looks great under bright sunshine. I also get less eyestrain reading eBooks and RSS on the matte E Ink display.
I love E Ink so much I doubt I am ever going back to LCD, but the E Ink display is not perfect: it is black and white (there is a color version but it is very grainy), and the E Ink display is also less responsive than an LCD.
It uses the native tab discard method to automatically reduce memory usage of inactive tabs. This way you can have lots of tabs without slowing the browser down.