More information and firmware: https://github.com/ElTangas/jtag2updi

Getting started with the new ATtiny chips: http://www.technoblogy.com/show?2OCH

megaTinyCore: https://github.com/SpenceKonde/megaTinyCore

Mini UPDI Programmer based on ATtiny1604: https://easyeda.com/wagiminator/attiny1604-updi-programmer

Development board for ATtiny x14/x04 series: https://easyeda.com/wagiminator/attiny-814-development-board-smd

Development board for ATtiny x16/x06 series: https://easyeda.com/wagiminator/y-attiny3216-development-board-smd