ESP8266
ESP8266 is a Wifi-enabled microcontroller made by Espressif Systems in Shanghai, China. With the help of the online development community & hundreds of examples online. ESP8266 is a powerful device that lets you build IoT prototypes & projects in no-time. You can pretty much control & connect anything electronic from the web or from a local server. Or you can even connect to your ESP8266 from other devices via Wi-Fi.