MOD-WIFI-ESP8266-DEV is a tiny development board that can add WIFI capabilties to existing boards. It uses espressif system's chip ESP8266EX. All chip signals are exposed for easier access.
ESP8266EX is very highly integrated SoC which includes Tensilica's L106 32-bit core processor; SRAM; power management unit; RF front end. ESP8266EX has a number of interfaces - I2C, SPI, SDIO and also a number of free GPIO pins. The chip allows the implementation of a WIFI TCP-IP stack with just few extra components beside the ESP8266EX.
MOD-WIFI-ESP8266-DEV is recommended for people that already have some experience with ESP8266.
2MB (16Mb) SPI flash memory