The Pixelspark Wi-Fi LED strip controller allows controlling of WS2801 ‘digital’ individually addressable LED strips (and, through software, possibly also for WS2812 based strips). Alternatively the board can be configured to provide I2C output for use with e.g. the MCP23017 daughter board.
The LED strip controller is based on the ESP8266 (ESP-01 module), which is very cheap (<$4) and provides connectivity to 2.4 GHz Wi-Fi networks. It obtains power over micro USB or a pin header. It allows selecting between 5V or 3.3V SPI bus power (SPI communications is always in 3.3V). When used for I2C, voltage shifting logic is in place to allow the I2C bus to operate at 5V.