I tried Xteinks trendy e-readers. Read this before you buy.

As Mashable's go-to BookTok, Kindle, and e-reader expert, it's my job to vet new products and know what's a gimmick and what's actually worth your money. The Xteink X4 e-reader is a mini e-reader that supposedly fits on the back of your phone. It's a solid idea: a mini Kindle you can slap on like a PopSocket and keep in your pocket. I've seen lots of people online excited about using the device as a companion to their Kindle.But the Xteink X4 won't be my new Kindle companion. It may be trendy, b