Of course it is integrated to the bitbox kernel (latest one), so that games will be able to make use of it ; it can be loaded with the bootloader - and the bootloader is available when you press reset+userbutton.
See the video for the demo hereafter (sound has been taken by my phone from the speakers so it's better in reality)
The project is hosted on github here : https://github.com/makapuf/bitbox-mod
See also the mailing list thread for details about it.
Thanks to the original code from Pascal Piazzalunga (http://www.serveurperso.com) !