Connectivity
USB/Serial
Bluetooth/Serial Creates a virtual serial port on your phone or PC. Standard serial port applications can use Bluetooth.
WIFI
Creates its own access point or connects to yours.
Built in web server. The server has full featured CNC control app that will run on your phone or PC in a browser. No app required.
Telnet sending of gcode
Push notifications (like...job done, get a text/email)
OTA (over the air) firmware upgrades.
SD card. Gcode can be loaded and run via WIFI.