Meet the LumiWatch: a projection smartwatch that turns your arm into a touchscreen, allowing you to interact with it in a whole new way. It comes with a 15-lumen projection module and touch sensor. According to the makers, the watch has an interactive area of 40 cm2.
The LumiWatch is powered by a 1.2GHz quad-core CPU with 450 MHz GPU. It has 4 GB flash memory and 768 RAM. It is based on Android 5.1. You can read the paper here.