https://github.com/MetalPhreak/ESP8266_GPIO16_TCP_Example
Microchip MCP23S17 SPI GPIO expander connected over the hardware HSPI module.
TCP Listener configured on port 33333. Send it a 2 byte command to turn the outputs on or off.
On Linux/OSX: echo -ne ‘\xFF\xFF’ | nc 192.168.5.1 33333
Could easily be expanded to a project controlling relays, triacs, etc.