The ESP-01 NanoBoard is a little "motherboard" for the well known ESP-01 modules (ESP8266) with some features for an easy use: on board serial-USB adapter (CH340), voltage regulator, external power connector, optional 16x GPIO expander, I2C connector, ESP-01 GPIO connector, expander connectors, automatic upload circuitry (Arduino IDE), configurable User key, Reset key, various control leds.
The idea was to reuse the ESP-01 for a board easy to program, ideal for beginners and classrooms:
More info here.