Our current batch of alexmos boards are compatible with SimpleBGC_GUI_2_0b3, but once you connect with that version GUI you can then upgrade to the latest version via the GUI. Future versions will have the latest firmware version at the time of manufacture.
Its best to only connect via USB (with motors disconnected) while you do the initial settings and firmware upgrade. If your motors are connected, please always connect your battery before connecting USB, as the USB does not provide enough power to drive the motors and it could damage your board.
For details on how to connect everything up, please see this post below