Some of Xteink’s credit card-sized e-readers are losing their best feature

The X3 is Xteink’s smallest e-reader. | Photo: Andrew Liszewski / The Verge The Xteink X4 and X3 are excellent alternatives to Kindles and Kobos if you want an e-reader that's as easy to slip into your pocket - just not out of the box. Both devices come with stock firmware that's clunky, limited, and occasionally confusing, but that can be easily fixed by plugging them into a PC to install alternative software called CrossPoint Reader which delivers a more polished user interface and improved functionality. But now buyers report Xteink is blocking the upgrade, which might depend on where you...