One of the most fascinating devices to be unveiled at Mobile World Congress was the Yotaphone 2, an Android smartphone equipped with a second, e-ink display on the backside of the handset. The face of the device works just as any other Android phone would, but then on the rear, you are presented with a 4.7-inch touch sensitive, "always on" e-ink screen that can be used to interact with calls, texts, emails, and social media.

The e-ink panel is not just easy to read, but it also has better battery life. Yota Devices stated that the 2,500mAh battery can power the phone for over 50 hours when using just the e-ink display. The phone also includes a Smart Power Mode, which shuts off the 5-inch, 1080p, full color AMOLED display, diverting energy to the much more efficient screen on the flip side.

While not every Android app work with the new Yotaphone's second screen, the company did release the phone's SDK to third-party developers, paving the way for more compatible apps.

Under the hood, the Android 4.4-powered Yotaphone 2 includes a 2.3GHz Snapdragon 800 CPU and 2GB of RAM, which is right in line with high-end Android smartphones. An 8-megapixel camera can be discovered on the back of the phone, with a 2-megapixel shooter up front.

Yota Devices has not formally publicized the availability, price, and launch information for its new Yotaphone 2. On the other hand, CNET reports that the device will first be sold in Russia, Europe, and the Middle East, with China and the United States projected to get the phone by the end of the year.