The Screenless Office
I’ve been meaning to put together a music player for my kids that uses one of: qr codes, bar codes, or NFC tags to select the music to play (no screen). The first two having surprisingly expensive readers (you can buy a crappy smartphone for the price of a dedicated usb always-on auto barcode or qr code scanner, and cheap webcams can’t focus correctly for the job of close-up code reading) and the latter confusing the hell out of me for any option that doesn’t use really expensive hobbyist-targeted tags ($0.50/tag or higher) have kept me from going beyond the googling phase.