ESP8266 DevKit Module V4 with CP2102 UART

Based around the ESP8266 ESP-12 and NodeMCU firmware this module provides an integrated Arduino-like hardware platform for developing wifi IoT applications using the Lua language.
May also be programmed using the C/C++ Arduino IDE by installing the ESP8266 libraries - select NodeMCU 1.0 (ESP-12E) Module
Programming/firmware flashing and power is via the onboard micro-USB connector - no need for an external power supply or USB-serial converter, just plug in to your Windows (with CP2102 driver installed), MAC or Linux computer.
Features 10 GPIO with each one capable of being configued for PWM, I2C, 1-wire.
There are many projects and usage guides on the internet - see http://nodemcu.com/index_en.html for more information.