We really like this “Back to the Future”-themed Flux Capacitor badge add-on (SAO) by Squaro Engineering made with our “After Dark” service (which features clear soldermask on black fiberglass substrate).
Checkout the GitHub repo for more: sqfmi/BTTF-BADGE
The board is also available an OSH Park shared project
Shared project by Rob Rehr (@mediumrehr) to connect Wii controllers to #badgelife add-on header:
Adapter board to attach Adafruit 8×8 LED Matrix board as #badgelife add-on (using the DC26 SAO 2×2 pin header)
KiCad design files:
OSH Park shared project:
#badgelife add-on adapter for Adafruit 8×8 LED matrix