12. L’Oreal

[Image from L’Oreal]
Measuring smaller than a fingernail, the battery-free wearable is 2mm thick and 9mm in diameter. It is an electronic sensor that can be stuck to sunglasses, clothes, shoes and even on the fingernail. When paired with the smartphone app, the device will give warnings related to the sun exposure of the user.
It is estimated to cost $40 and has a global launch plan of 2019 with limited available in the U.S. in summer 2018.