The Xbee System is a 2.4GHz Wifi Receiver that is connectet to an Arduino or mostly to a Marcduino. It receives commandos from a smartphone app and the Marcduino then triggers sequences.
The Xbee system needs The XBee S6B (XB2B-WFST-001), the Sparkfun “breakout”board (WRL-11373) and a 2.4GHz antenna (3 or 6dB gain)


The software for programming the Xbee can be found here:
https://www.digi.com/products/embedded-systems/digi-xbee/digi-xbee-tools/xctu