Current version is v1.0.
Use it with TeaCup Firmware.
Use this command to flash Nano under Linux:
avrdude -c arduino -b 57600 -p atmega328p -P /dev/ttyUSB0 -U flash:w:teacup.hex
and you will got the teacup.hex with the following settings:
others settings are default.
It was tested on my Mendel90.