Just a Sign.

Sign is a next-gen smartphone that has very little to do with existing phones. It is loaded with solar energy. It does not plug into a solar charger, you just expose it to sunlight so that the battery is charged at 80%. Sign has a decidedly mystical appearance. A priori,no visible screen or keyboard. In the end, just an opaque body with a concave lens anda back. In reality, it does have a screen but it only appears when it's active. The phone uses a transparent OLED display. The concave is a touchpad ergonomic visibly practice to navigate the phone menus. 

This concept phone solar and mysterious is not yet ready to disembark. Most of the technologies it requires are not yet mastered at the moment.