Phones with second screens fascinate me. The second display -- on the back, front, or folded in like a book -- is meant to increase your screen space, but rarely ever works (we have the sad proof). And still, they try: Samsung and LG, Kyocera and the more obscure YotaPhone with its e-ink back.
After a lull in the trend, Android phone maker Meizu is jumping into the experiment with the Meizu Pro 7 and Pro 7 Plus, a pair of phones with a swipeable 2-inch AMOLED touchscreen on the back. This isn't a whole mini phone on your phone.
The Pro 7's secondary display will broadcast the time and weather forecast, show you your alerts and beam out your musical selection. You can also tap it to help take a selfie with the phone's two rear 12-megapixel cameras (ostensibly for a higher-quality pic than the front-facing camera).
The mini screen on the back might look a little strange to those of us used to smooth backings or a case, but it's not so large that it takes over your entire phone backing (and sucks your battery dry).
Mostly, I think it could stand a chance of being useful because it's so targeted, and so out of the way. As a matter of habit, I turn my phone on its face when I'm not using my phone. Being able to quickly glance at the weather or monitor an incoming call could be handy.
You would definitely need a specialized case with a see-through window to take advantage of that second screen.
Brush up on all the dual-screen smartphone disasters, and check out the Meizu Pro 7's other specs below.